Italian Spaghetti with Leek Cream, 'Nduja and Hazelnuts | Spaghetti con Crema di Porri, 'Nduja e Nocciole
This is a modern Italian plate built from three things that were never meant to meet: leeks sweated until they collapse into a pale sweet cream, 'nduja from Calabria rendered into fiery orange oil, and hazelnuts from Piedmont toasted and crushed at the last moment. The leek carries the sweetness, the 'nduja carries the heat and the salt, the hazelnut carries the crunch and a roasted note that holds the other two together.
None of it works without restraint. 'Nduja is one of the most aggressive ingredients in the Italian pantry, and used with a heavy hand it wipes out the leek entirely and leaves a plate of chile and pork fat. Used at the right weight, and rendered slowly rather than thrown into a hot pan, it becomes a seasoning rather than a sauce, and the leek cream remains the thing you taste first.
Yield: 4 servings. Prep: 20 minutes. Cook: 35 minutes. Total: about 55 minutes. Difficulty: intermediate. Course: primo piatto. Origin: contemporary Italian cooking, drawing on Calabria for the 'nduja and Piedmont for the hazelnut.
The Story
'Nduja comes from Spilinga, a small town on the slopes of Monte Poro in the province of Vibo Valentia, on the Tyrrhenian side of Calabria. It is a spreadable cured salume made from pork fat and the trimmings of the pig, blended with a very large proportion of local sweet and hot peperoncino, stuffed into a casing and smoked and aged for several months. The name almost certainly descends from the French andouille, carried south during the Napoleonic period, though what Calabria built from the idea bears no resemblance to the original. For most of its life it was food for people who could not afford the better cuts.
The hazelnut belongs to the opposite end of the country. The Tonda Gentile Trilobata grown in the Langhe of Piedmont, protected as Nocciola Piemonte IGP, is regarded as the finest cooking hazelnut in Italy, prized for its thin skin and the depth it develops when roasted. Campania has its own, the Nocciola di Giffoni IGP, which works equally well here. Hazelnuts have been ground into sauces in Piedmont for centuries, so using them on pasta is less of an invention than it looks.
The leek is the quiet member of the three. Italy grows it seriously in Piedmont, where the Porro di Cervere is a Slow Food presidium, and in the Veneto. Italian cooking has generally treated it as a base rather than a subject, something to soften at the start of a soffritto, so giving it the centre of the plate is the one genuinely modern move here.
Ingredients
For the pasta
Dried spaghetti, bronze die, 14 oz (400 g)
Water for boiling, 5 quarts (4.7 liters)
Fine sea salt for the water, 4 tsp (24 g)
For the leek cream
Leeks, white and pale green parts only, 1 lb (450 g) after trimming, about 3 large
Unsalted butter, 2 tbsp (28 g)
Extra virgin olive oil, 2 tbsp (30 ml)
Light vegetable stock or water, 1 cup (240 ml)
Whole milk, 1/3 cup (80 ml)
Fine sea salt, 3/4 tsp (4 g)
Ground white pepper, 1/4 tsp
For the nduja
'Nduja di Spilinga, 2 1/2 oz (70 g)
Extra virgin olive oil, 1 tbsp (15 ml)
For finishing
Shelled hazelnuts, skin on, 1/3 cup (45 g)
Finely grated lemon zest, from 1/2 lemon
Pecorino Crotonese, finely grated, 2 tbsp (12 g), optional
Flat leaf parsley or chives, finely chopped, 1 tbsp
Extra virgin olive oil, raw, for finishing
Preparation
Step 1
Trim the leeks hard. Cut away the roots and the tough dark green tops, keeping only the white and the pale green, then split each leek lengthwise and slice it thinly across. Leeks grow with soil packed between their layers, so put the slices in a bowl of cold water, agitate them, and lift them out with a sieve rather than pouring the bowl out, which tips the grit straight back over them. Repeat until the water stays clear, then drain well.
Step 2
Sweat the leeks with no colour at all. Melt the butter with the olive oil in a heavy saucepan over low heat, add the leeks and a pinch of the salt, cover, and cook for 18 to 22 minutes, stirring every few minutes. They should go completely soft and translucent without taking on any gold, because browning turns their sweetness into something closer to caramelised onion and shifts the whole plate. If the pan starts to catch, add a spoonful of water and lower the heat further.
Step 3
Add the stock and the milk, bring to a bare simmer, and cook uncovered for 5 minutes more. Transfer everything to a blender with the rest of the salt and the white pepper and blend on high until completely smooth, at least a full minute. Pass the purée through a fine mesh sieve back into the pan, pressing it with a ladle. The sieve catches the fibrous strands the blade cannot break, and it is the difference between a rustic sauce and a cream that coats the pasta evenly.
Step 4
Toast the hazelnuts on a small tray in a 325°F (165°C) oven for 10 to 12 minutes, until they smell sweet and the skins have cracked and darkened. Tip them onto a clean cloth, fold it over and rub them briskly to remove most of the skins, which are bitter, then let them cool. Crush them coarsely with the flat of a knife or the base of a pan rather than chopping them fine. You want irregular pieces that still read as crunch on the plate.
Step 5
Render the 'nduja gently. Put it in a wide saute pan with the tablespoon of olive oil over low heat and break it up with a wooden spoon. Over three to four minutes the fat melts, the paste loosens and the pan fills with bright orange oil. Keep the heat low: pushed hard, the peperoncino scorches and turns acrid, and the pork fat separates into something greasy. Take the pan off the heat as soon as it has become a loose, fragrant oil.
Step 6
Bring the water to a rolling boil and salt it with 4 tsp (24 g), which is less than you would normally use, because the 'nduja and the Pecorino both arrive salty and there is no way to take salt out later. Add the spaghetti, stir once, and cook it for two minutes less than the packet says. Reserve a full cup of the cloudy cooking water before draining, and drain the pasta while it is still firmly al dente.
Step 7
Warm the leek cream in the 'nduja pan over medium low heat, stirring the rendered orange oil through it so it marbles rather than disappears. Add the drained spaghetti and toss continuously, loosening with the reserved pasta water a few tablespoons at a time until the sauce coats every strand and slides freely. Take the pan off the heat, add the Pecorino if you are using it, toss once more, and finish with the crushed hazelnuts, lemon zest, herbs and a thread of raw olive oil.
Plating
Use warm wide bowls with a flat base, held at around 140°F (60°C). The leek cream tightens noticeably as it cools and a cold bowl turns a glossy sauce into a paste in under a minute.
Twist a quarter of the spaghetti into a loose upright nest with tongs and a large spoon and set it slightly off centre, then spoon any cream left in the pan around its base rather than over the top. The visual logic is a pale nest with orange breaking through it, so drag a teaspoon of the rendered 'nduja oil in two or three short lines across the bowl. Scatter the crushed hazelnuts last, over and around the pasta, so none sit under the sauce and soften, then finish with the lemon zest and a few drops of raw olive oil and send it immediately.
Professional Technique
The controlling technique here is the sweat, not the blend. Leeks contain a large amount of water and a modest amount of sugar, and the object of 18 to 22 minutes under a lid over low heat is to drive off part of that water and concentrate the sugar while staying below the temperature at which browning begins. A lid keeps enough moisture in the pan that the slices steam as much as they fry, because a leek that catches colour develops the savoury notes of a soffritto and stops tasting like leek.
The second is the rendering of the 'nduja, which is a fat extraction rather than a cooking step. 'Nduja is roughly half fat by weight, and its flavour and its heat both live in that fat: capsaicin and the aromatic compounds of peperoncino are fat soluble, so melting the fat slowly releases them into a medium that can then be distributed evenly through a sauce. Added cold it stays in lumps and the heat arrives in bursts; rendered hard, the sugars in the peperoncino burn. Low and slow is the only window that works.
Texture and Moisture Control
This sauce is carried by vegetable purée rather than by starch alone, so it behaves differently from an oil based pasta sauce. The cream is already thick when it leaves the sieve, and the pasta water is what turns it into something that moves. Add it gradually and judge by how the sauce falls off a lifted strand: it should coat and slide, not cling in clots. If it turns watery, keep tossing over the heat for another thirty seconds and the starch will pull it back. It also tightens as it stands, which is why a spoonful of hot water is kept back for the bowls.
The hazelnuts are a moisture problem of their own. Crushed and added at the last second they stay brittle, but they absorb liquid quickly and within two or three minutes of sitting in the sauce they turn soft and lose the contrast that justifies them. Keep them dry and away from the stove until the pasta is already in the bowl. For the pasta itself, drain two minutes early so it finishes in the cream and absorbs flavour rather than water, and aim for a strand that still resists slightly at the centre.
Professional Mise en Place
The leek cream and the hazelnuts are both made in advance, which leaves only the rendering and the tossing to be done once the pasta is in the water.
Equipment and tools
High speed blender and a fine mesh conical sieve
Heavy saucepan with a tight lid for sweating the leeks
Wide saute pan, 12 inch (30 cm), for rendering and tossing
Long tongs and a heatproof cup for the pasta water
Prepared ahead
Leek cream blended, strained and refrigerated, up to 2 days
Hazelnuts toasted, skinned and crushed, kept airtight, same day
'Nduja weighed and brought to room temperature so it melts evenly
Lemon zested, herbs chopped, Pecorino grated, plates warming
Service setup
Leek cream warm over a low flame, slackened with hot stock if it has set
Saute pan on the burner beside the pasta pot, oil measured
Crushed hazelnuts in a dry bowl well away from any steam
Bowls warm, raw olive oil open, everyone seated before the pasta drains
Chef Tips
Buy real 'nduja di Spilinga if you possibly can, and taste it before you weigh it. Commercial versions vary from mildly warm to genuinely fierce. Start with half the quantity, render it, taste the oil, and add the rest only if the plate can take it.
Save the dark green leek tops. They are too fibrous for the cream but they make a light stock in twenty minutes with a carrot, a stick of celery and a bay leaf, and that stock is exactly what the recipe asks for further down.
Skin the hazelnuts properly. The papery skin is bitter and it also refuses to stick to the pasta, so it ends up as dark specks in the bottom of the bowl. Rubbing them in a cloth while they are still warm removes most of it in about thirty seconds, and a few stubborn patches left behind do no harm.
If the finished plate tastes flat, the answer is almost always acid rather than salt. Lemon zest does most of that work; a very small squeeze of juice, added off the heat, does the rest without thinning the sauce.
Common Mistakes
Browning the leeks. Any gold in the pan turns the sauce into something that tastes of caramelised onion and the delicate sweetness disappears. Keep the heat low, the lid on, and add a spoonful of water if the pan begins to catch.
Using too much 'nduja. It is a seasoning here, not the sauce, and past about 3 oz (85 g) for four servings it simply erases the leek. Weigh it rather than eyeballing it, and remember that its heat builds on the palate over the course of the plate.
Adding the 'nduja cold. Stirred into the pasta as a paste it stays in lumps and the heat arrives unevenly. Render it slowly in a little oil first.
Skipping the sieve. Leeks are fibrous and even a powerful blender leaves threads behind, which catch on the tongue and make the sauce feel rough. Two minutes with a fine mesh sieve is what turns it into a cream.
Salting the pasta water as usual. Between the 'nduja and the Pecorino the dish already carries plenty of salt. Use about two thirds of what you normally would and correct at the end.
Adding the hazelnuts too early. They soak up the sauce within a couple of minutes and go soft, and the only textural contrast on the plate is gone. They are the last thing that touches the bowl, after the pasta is already in it.
Wine Pairing
Three things have to be handled: the chile heat of the 'nduja, the fat of the pork and the milk, and the sweetness of the leek. Heat magnifies alcohol and tannin, so the wines below are all dry, moderate in alcohol and firm in acidity, and the reds among them are chosen for freshness rather than structure.
Cirò Bianco DOC: The Calabrian answer, made from Greco Bianco on the Ionian side of the region, and the most geographically honest match for 'nduja. It is dry, moderately alcoholic and cut with a citrus and white peach acidity that lifts the pork fat off the palate without adding weight. Its faintly bitter finish holds its own against the peperoncino instead of being burned away by it.
Greco di Tufo DOCG: From inland Campania, and the best choice if you want a white with real substance under the cream. Greco has a broad, almost waxy texture and a mineral edge that sits comfortably beside rendered pork fat, while its acidity keeps the plate from turning heavy. Its stone fruit and toasted nut notes pick the hazelnut up directly.
Falanghina del Sannio DOC: The everyday option and the most refreshing of the three whites. Brisk green apple and citrus acidity slices through the milk and butter in the leek cream, and the moderate alcohol means the chile is not amplified on the finish. A good bottle carries a bitter almond note that runs alongside the toasted hazelnuts rather than competing with them.
Cirò Rosso Classico DOC: The red that belongs to the same soil as the 'nduja, built on Gaglioppo. Its tannin is fine and dusty rather than grippy, which matters a great deal with chile, and it brings sour cherry and dried herb against the sweetness of the leek. Serve it at around 60°F (16°C), cooler than a full bodied red, and it stays lively instead of turning warm and alcoholic.
Etna Rosso DOC: The most elegant pairing here, made from Nerello Mascalese on volcanic slopes at altitude. It is pale, high in acidity and light in tannin, closer to a northern red than a southern one, and that lightness is exactly what a spicy plate needs. Its smoky mineral character echoes the cured, lightly smoked quality of the 'nduja without adding more weight to a rich dish.
Storage & Reheating
The components keep much better than the finished plate, so make ahead rather than store after. The leek cream holds in an airtight container in the refrigerator for up to 2 days and freezes for up to 2 months, though blend it again briefly after thawing because the milk separates. Crushed toasted hazelnuts keep airtight at room temperature for a week, and 'nduja keeps for months in its casing in the refrigerator, wrapped once opened.
Dressed pasta is a different matter and should be eaten straight away. If you have leftovers, cool them quickly and refrigerate them in an airtight container for up to 2 days. Do not freeze the finished dish: the spaghetti breaks down on thawing and the cream splits. To reheat, put the pasta in a wide saute pan with 2 tbsp (30 ml) of water or milk, cover it, and warm it over medium low heat for two to three minutes, tossing once or twice. A microwave overcooks the strands and tightens the cream.
Nutrition
Per serving, based on 4 servings:
Calories: 710 kcal
Total Fat: 33 g
Saturated Fat: 10 g
Trans Fat: 0 g
Unsaturated Fat: 21 g
Cholesterol: 40 mg
Sodium: 780 mg
Total Carbohydrates: 82 g
Fiber: 6 g
Total Sugars: 7 g
Added Sugars: 0 g
Protein: 19 g
Lactose: 1.5 g
Principal micronutrients: vitamin A, vitamin K, vitamin E, folate, iron, manganese, magnesium, phosphorus
These figures are estimates. Sodium moves the most, since 'nduja varies widely in salt between producers and the optional Pecorino adds more, and the fat depends on how much of the rendered pork fat stays in the pan.
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