Porri di Cervere Gratinati al Castelmagno (Italian Piedmont Leek Gratin)

2 hours ago
3 min read

Story of the Dish

Cervere leeks is a distinctive ingredient in the cooking of Piemonte, and its character becomes especially expressive when balanced with butter, milk and aged cheese.

This preparation is built as a true gratin. A light béchamel connects the Cervere leeks with Castelmagno DOP, while Parmigiano Reggiano and butter create the roasted surface.

The finished dish should remain ingredient driven: tender and creamy inside, but with recognizable pieces beneath an irregular, deeply golden crust.

Ingredients

8 medium Cervere leeks, about 3 lb (1.35 kg)
5 oz Castelmagno DOP (140 g)
1/2 cup dry white wine (120 ml)
1/2 cup light vegetable stock (120 ml)
3 tbsp unsalted butter (45 g)
3 tbsp all purpose flour (30 g)
2 1/2 cups whole milk (600 ml), warm
6 oz Castelmagno DOP (170 g), grated or sliced
1/2 cup Parmigiano Reggiano (45 g)
2 tbsp unsalted butter (30 g), for finishing
Fine sea salt, white pepper and nutmeg, to taste

Preparation

Halve the leeks lengthwise and wash carefully between the layers. Brown cut side down in butter, add white wine and stock, cover and braise 10 to 12 minutes. Uncover and reduce the liquid nearly completely before assembly.

Prepare the béchamel by cooking butter and flour for 2 minutes without browning. Gradually whisk in warm milk and simmer 6 to 8 minutes until lightly thickened. Season cautiously.

Butter a wide shallow gratin dish. Add a thin layer of béchamel, arrange the Cervere leeks, distribute Castelmagno DOP between the pieces and spoon the remaining sauce lightly over and between them. Finish with Parmigiano and butter.

Bake at 400°F (205°C) for 18 to 25 minutes until bubbling. Broil 2 to 4 minutes, watching continuously, until the surface is deeply golden. Rest 8 to 10 minutes before serving.

Professional Technique

Moisture management is the central technical point. The Cervere leeks must enter the baking dish nearly tender but not waterlogged; otherwise liquid released in the oven will thin the béchamel and weaken the crust.

Castelmagno DOP provides the regional flavor and melting character, while Parmigiano is concentrated near the surface for stronger browning. Baking integrates the dish; broiling is the separate final stage that creates the gratin.

Chef Tips

Choose the freshest, firmest Cervere leeks available.
Keep pieces substantial enough to survive the second cooking.
Keep the béchamel relatively light because Castelmagno DOP will thicken it in the oven.
Season cautiously because aged cheese adds salt as moisture evaporates.
Use a wide shallow dish and broil only at the end.

Common Mistakes

Overcooking the Cervere leeks before assembly.
Failing to remove excess moisture from the Cervere leeks.
Making the béchamel too thick.
Using so much cheese or sauce that the main ingredient disappears.
Skipping the final high heat gratination.

Wine Pairing

Roero Arneis DOCG — Freshness and acidity balance the béchamel, butter and browned cheese while respecting the main ingredient.

Gavi DOCG — Freshness and acidity balance the béchamel, butter and browned cheese while respecting the main ingredient.

Dolcetto d’Alba — Freshness and acidity balance the béchamel, butter and browned cheese while respecting the main ingredient.

Nebbiolo d’Alba — Freshness and acidity balance the béchamel, butter and browned cheese while respecting the main ingredient.

Barbera d’Alba DOC — Freshness and acidity balance the béchamel, butter and browned cheese while respecting the main ingredient.

Storage & Reheating

Store tightly covered in the refrigerator for up to 3 days. Reheat at 350°F (175°C), covered at first and uncovered for the final 5 minutes. Finish briefly under the broiler to restore the crust.