Italian Watermelon, Seared Tuna and Sesame Salad | Insalata di Anguria, Tonno Scottato e Sesamo
This salad is built on two Sicilian summer ingredients that spent centuries within sight of each other without ever meeting on a plate. Watermelon comes off the sandy coastal plains between Trapani and Siracusa. Tuna comes from the tonnare, the fixed trap fisheries that worked the same water for a thousand years. The dish that joins them is recent, but neither ingredient is borrowed.
The tuna is seared hard and fast outside and left raw in the middle, then sliced so both states show in the same piece. The watermelon is cut thick, drained and left cold. Between them sits a dressing of orange juice, lemon, rice vinegar, soy and ginger, and over everything goes toasted sesame, which is no imported flourish here: Sicily has grown sesame since the Arab period.
The salad works on contrasts held in tension: cold sweet fruit against warm savoury fish, soft melon against the dense grain of the tuna, salt against sugar. None of it survives carelessness. Dress the fruit early and you get a pink puddle; cook the tuna a minute too long and you get a grey block.
Yield: 4 servings as a contorno or a light antipasto. Prep: 30 minutes. Draining: 30 minutes. Cook: 2 minutes. Total: about 1 hour. Difficulty: intermediate. Course: contorno or antipasto. Region: Sicily, the western and southeastern coasts.
The Story
Watermelon reached Sicily with the Arabs, along with citrus, rice, sugar cane and sesame. The sandy soil behind the coast at Marsala, Mazara and the Siracusano drains fast and warms early, which is what a watermelon wants, and by high summer the fruit is stacked outside every roadside stand between Palermo and Pachino. Sicilians never treated it purely as fruit to be eaten in wedges: gelo di melone, the jellied watermelon pudding of Palermo studded with jasmine and chocolate, is proof that the island has always been willing to cook with it. Sesame arrived on the same boats. Cubbaita, the hard sesame and honey brittle sold at every village sagra, descends directly from a medieval Arab sweet.
The tuna comes from a far older tradition. The tonnare of Favignana, Bonagia and Scopello intercepted bluefin on their spring migration into the Mediterranean, in chambered nets that ended in the mattanza. Those fisheries closed one after another through the twentieth century, but the knowledge survived them: how to cut a tuna, which muscle does what, and the habit of treating the fish as meat rather than as something delicate. Mazara del Vallo is still where the best tuna for this comes ashore.
So when sesame lands on a plate of Sicilian tuna it is not a nod to Japan, whatever the searing technique may owe to it. The technique is modern; the ingredients have shared the same island for a thousand years.
Ingredients
For the salad
Seedless watermelon, trimmed of rind, 1 1/2 lb (680 g)
Tuna loin, centre cut, sashimi grade, 1 lb (450 g)
English cucumber, 1 medium, about 7 oz (200 g)
Scallions, green and pale parts, 3
Fine sea salt, 1/2 tsp (3 g)
Grapeseed oil or another neutral oil, 1 tbsp (15 ml)
Freshly ground black pepper, to taste
For the citrus and soy dressing
Extra virgin olive oil, 3 tbsp (45 ml)
Freshly squeezed orange juice, 2 tbsp (30 ml)
Freshly squeezed lemon juice, 1 tbsp (15 ml)
Rice vinegar, unseasoned, 1 tbsp (15 ml)
Light soy sauce, 2 tsp (10 ml)
Fresh ginger, finely grated, 1 tsp (3 g)
Honey, 1/2 tsp (3 g)
For finishing
White sesame seeds, toasted, 2 tbsp (18 g)
Black sesame seeds, 1 tsp (3 g)
Finely grated orange zest, from 1/2 orange
Flaky sea salt, a pinch per plate
Small mint leaves, 12
Extra virgin olive oil, a few drops per plate
Preparation
Step 1
Cut and drain the watermelon. Remove the rind and any pale flesh next to it, then cut the red flesh into cubes of about 1 inch (25 mm). Do not cut it small: a cube that size keeps a cold centre and holds its shape under the dressing, while a fine dice turns to slush. Spread the cubes in one layer on a lined tray, sprinkle with a scant 1/4 teaspoon of fine sea salt and refrigerate uncovered for 30 minutes. The salt pulls out a surprising amount of free water, which is the point, and sharpens the sweetness.
Step 2
Prepare the cucumber, the scallions and the sesame. Halve the cucumber lengthways and scrape out the wet seed core, the second largest source of stray water in the bowl, then cut the halves into half moons about 1/4 inch (6 mm) thick. Slice the scallions thinly on an angle, drop them into ice water for 5 minutes and drain well. Toast the white sesame in a dry pan over medium heat for 2 to 3 minutes, moving it constantly, and tip it onto a cold plate the moment it smells nutty. Leave the black seeds raw.
Step 3
Build the dressing. Whisk the orange juice, lemon juice, rice vinegar, soy sauce, ginger and honey together until the honey dissolves, then add the olive oil in a thin stream while whisking so it emulsifies loosely. Taste it alone: it should read sweet first, then sharp, then salty, with the ginger behind all three. If it tastes flatly salty the soy is winning and needs another teaspoon of orange juice. Keep it cold and whisk it again before use.
Step 4
Trim and dry the tuna. Buy a centre cut piece of loin rather than a tail piece, one block about 2 inches (50 mm) square in section. Trim away any sinew and the dark bloodline, which is metallic and has no place here. Pat the block dry on all four sides and leave it uncovered on a rack in the refrigerator for 15 minutes. A wet surface will not sear, it will steam, and that difference is the whole dish.
Step 5
Sear and rest the tuna. Season the block with salt and pepper at the last moment. Heat a heavy pan over high heat until the neutral oil is just short of smoking, lay the block down and count 20 to 30 seconds per face, turning onto each of the four long sides in turn. You are building a brown crust no more than 1/8 inch (3 mm) deep and leaving the core raw and cool. Rest it on a rack for 3 minutes, never on a plate, where residual heat keeps cooking the underside.
Step 6
Slice, dress and assemble. Cut the block across the grain into slices about 1/3 inch (8 mm) thick with the sharpest knife you own, one clean drawing stroke per slice rather than a sawing motion, so the seared rim stays attached to the ruby centre. Drain the watermelon hard and pat the cubes dry. Combine them in a chilled bowl with the cucumber and scallions, add two thirds of the dressing and turn everything over two or three times only, with a spatula rather than tongs. Overworking bruises the melon. Plate within a minute.
Plating
Chill the plates. This is one of the few dishes where a cold plate is a requirement rather than a mistake, because the melon has to stay cold against a warm piece of fish. Use wide shallow bowls, white or pale. Spoon the dressed watermelon, cucumber and scallions into a loose low mound slightly off centre, leaving the pieces where they fall, and lean three or four slices of tuna against it, seared edge facing the diner, rather than covering the fruit. The two should read as adjacent, not stacked, so fruit and fish can be taken separately as well as together.
Finish in order: the reserved dressing spooned around the base of the salad and not over the tuna, white sesame over the fruit, black sesame over the fish, orange zest across both, a pinch of flaky salt on the tuna only, mint tucked into the salad, a few drops of good olive oil last. Serve immediately. The dish has about four minutes on the plate before the melon starts to weep.
Professional Technique
Salting and draining the watermelon is what makes this salad possible, and it is the step most cooks leave out. Watermelon is roughly 92 percent water held in large thin walled cells that rupture under salt, acid or pressure. Dress it undrained and the dressing pulls that water out on the plate within two minutes, thinning itself to nothing. Thirty minutes of light salting removes the free water in advance, and the cubes that come off the tray are firmer, denser and sweeter, because the remaining sugars are less dilute.
The sear depends on a contradiction: maximum surface heat, minimum penetration. Tuna muscle is lean, has little connective tissue and sets at a low temperature, so the window between raw and chalky is narrow. A very hot dry pan, a dry fish surface and 20 to 30 seconds per face give Maillard browning outside while the thermal front travels only a few millimetres inward. A moderately hot pan cooks a grey band a centimetre deep before any colour appears. High heat and short time is the only route.
The third technique is the loose emulsion. A tight stable emulsion, the kind a blender gives you, coats the watermelon in a film and mutes it. This salad wants a dressing that separates gently on the plate, so the diner gets olive oil on one bite and citrus and soy on the next, which is why the oil goes in by hand and why only two thirds of it goes into the bowl.
Texture and Moisture Control
Three textures have to be protected and each fails on its own clock. The watermelon must stay crisp and cold and fails over about ten minutes once dressed. The tuna must stay dense and cool in the middle and fails within three minutes on a warm surface. The sesame must stay dry, which is why it is scattered at the very end: it softens within a minute of contact with dressing.
Moisture moves in one direction here, out of the fruit, and everything is arranged to intercept it. The salting takes the first and largest wave, the cucumber seed core the second, draining the scallions the third. The rest is handled by tossing at the last possible moment and keeping bowl, plates and fruit properly cold, since cold cell walls leak more slowly than warm ones. Temperature contrast is itself a texture: the melon at around 40°F (4°C), the tuna warm on its crust and cool in its core. If the fish has to wait, wait with the fruit undressed, because fruit recovers from waiting and dressed fruit does not.
Professional Mise en Place
Almost every element can be prepared ahead and almost nothing assembled ahead. Plan the work so the last ninety seconds contain only the sear, the slice and the toss.
Equipment and tools
Heavy cast iron or carbon steel pan that holds high heat
The sharpest long bladed knife available
Wire rack over a tray, for drying and then resting the tuna
Lined tray for draining the watermelon, chilled mixing bowl
Small whisk and a bowl for the dressing
Prepared ahead
Dressing, whisked and refrigerated, up to 1 day ahead
Sesame seeds toasted and cooled, up to 3 days ahead in a sealed jar
Watermelon cut and salted on its tray, up to 2 hours ahead, refrigerated
Cucumber seeded and cut, scallions sliced and shocked, up to 4 hours ahead
Tuna trimmed into a block, uncovered on a rack, up to 1 hour ahead
Service setup
Plates in the refrigerator, not in a warming drawer
Pan heating while the watermelon is drained and dried
Dressing, sesame, zest, salt and mint within reach of the plating area
Slicing board wiped clean and dry, knife honed
Nothing dressed until the tuna is rested and ready to cut
Chef Tips
Buy the tuna from someone who will tell you when it landed, and buy a centre cut block rather than ready cut steaks, which are usually too thin to sear without cooking through. If a steak is the only option, choose the thickest on the counter and sear two faces rather than four.
Taste the watermelon before you commit. Fruit that is pale or faintly sweet cannot be corrected by dressing, and it makes a salad that tastes of soy and nothing else. A good melon is heavy for its size, sounds hollow when tapped and has a creamy yellow field spot where it lay on the ground.
Keep the soy exactly where it is. Two teaspoons in the whole dressing sounds like nothing, and that restraint is deliberate: soy supplies savoury depth under the citrus, it does not announce itself. Doubled, it turns the dish into a marinade and flattens the watermelon. For more savoury weight add flaky salt at the end instead.
The dish takes one substitution well and most badly. Cantaloupe works in place of watermelon, firmer and needing less draining. Swordfish in place of tuna does not: it wants to be cooked through and turns dry seared rare. If good tuna is unavailable, serve the fruit and dressing alone as a plain contorno.
Common Mistakes
Dressing the watermelon in advance. Acid and salt pull water out of the fruit within minutes, and a salad dressed a quarter of an hour early arrives in a pool of pink liquid with the dressing diluted to nothing. Toss it in a chilled bowl no more than two minutes before plating.
Searing wet tuna in a lukewarm pan. A damp surface steams, and a moderate pan cooks a wide grey band inward before any crust appears. Dry the block thoroughly, take the pan to just below smoking and count seconds rather than watching colour.
Slicing the tuna ahead of service. Cut faces of raw tuna oxidise and dull within fifteen minutes, and no dressing hides it. Sear, rest three minutes, slice, plate, without pause.
Toasting the sesame too far. Sesame goes from fragrant to bitter in under thirty seconds and keeps cooking after the heat is off. Tip the seeds onto a cold plate the moment they smell nutty.
Wine Pairing
Etna Bianco DOC: Carricante grown on volcanic soil on the eastern slope, and the most precise match on the list. Its very high acidity and stony saline finish cut through the sweetness of the watermelon instead of being swamped by it, which is how most whites fail against fruit. A bottle with a year or two of age has the texture to sit beside the seared crust, and its citrus peel bitterness picks up the orange zest.
Grillo Sicilia DOC: The western Sicilian answer, from the same country as the tuna. Grillo brings ripe citrus, green herbs and a saline edge that meets the soy on its own terms, reading as savoury rather than fighting it. Rounder and less acidic than Etna Bianco, and the better choice if your melon is on the sharper side of ripe.
Vermentino di Gallura DOCG: Grown on decomposed granite in northern Sardinia and built for this kind of plate. The salinity stands up to the soy, and the bitter almond finish gives the toasted sesame something to lean on, while its lift of citrus and wild herbs works with the mint and ginger rather than colliding with them.
Cerasuolo d'Abruzzo DOC: A properly structured dry rose, deeper and firmer than most, and the bottle for when the tuna rather than the fruit is the point. Its red fruit and light tannic grip handle the seared crust and the raw fish together, with enough acidity to keep the melon in check. Serve it at around 50°F (10°C).
Storage & Reheating
Assembled, this salad does not store at all. Within half an hour in the refrigerator the watermelon has wept, the dressing thinned, the sesame softened and the tuna firmed and dulled. Scale the recipe to what will be eaten in one sitting.
Unassembled, the components behave well. The dressing keeps refrigerated in a sealed jar for 3 days and needs only a whisk before use. Toasted sesame keeps 3 days in an airtight jar at room temperature and should never go in the refrigerator, where it takes on moisture. Cut and salted watermelon holds on its covered tray for up to 4 hours, best within two. Cucumber and scallions keep a day in a lined sealed box.
Seared tuna is best eaten within minutes, but a whole unsliced block can be seared, cooled quickly and refrigerated tightly wrapped for up to 24 hours, then brought to cool room temperature for 15 minutes before slicing. Never reheat it: warming seared tuna cooks the raw core through. Freeze no part of this dish. Thawed watermelon collapses into liquid and thawed raw tuna loses the grain that holds a clean slice.
Nutrition
Per serving, based on 4 servings:
Calories: 330 kcal
Total Fat: 18 g
Saturated Fat: 3 g
Trans Fat: 0 g
Unsaturated Fat: 15 g
Cholesterol: 45 mg
Sodium: 520 mg
Total Carbohydrates: 16 g
Fiber: 2 g
Total Sugars: 12 g
Added Sugars: 1 g
Protein: 27 g
Lactose: 0 g
Principal micronutrients: vitamin A, vitamin C, vitamin B12, niacin, selenium, potassium, magnesium, lycopene
These figures are estimates. Most of the salting salt leaves with the drained watermelon liquid, so the real sodium depends mainly on the soy sauce and on the flaky salt added at the end.
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