Béchamel Sauce à L’Ancienne with Lardo

Melt the butter in a saucepan over low heat. Once the butter starts to foam, add the sifted flour and stir until the mixture begins to bubble. Cook for one minute without letting it brown. Remove from heat and set aside.

Line the interior of a deep oven-safe mold or dish (with at least a 4-liter capacity) with thin slices of lardo. Add white peppercorns, one peeled whole onion studded with a clove, and a bay leaf. Refrigerate.

Heat the milk with the second onion, which should also be studded with cloves, along with a bay leaf and the bouquet of fresh herbs. Let it simmer for about 30 minutes.

Strain half of the hot milk and add it to the prepared roux using a fine sieve or chinois. Whisk well to integrate the ingredients. Cook over low heat, stirring constantly, for 5 more minutes.

Strain the remaining milk and repeat the previous step, adding it to the first batch of sauce.

Season with nutmeg and let the mixture simmer over low heat, stirring constantly, until it reaches a thick consistency.

Strain the sauce one last time over the prepared mold lined with lardo. Add the canned mushrooms.

Cover the mold with aluminum foil and bake in a preheated oven at 175°C (347°F) for 30 minutes.