Ingredients: All-purpose flour, Milk, Eggs, Salt, Unsalted butter divided, === FOR THE FILLING ===, Shiitake mushrooms stems, And cut in half, Dried porcini mushrooms, Hot water for 10 minutes, Spanish onion finely, Extra-virgin olive oil, White truffle oil, === FOR THE SAUCE ===, Milk, Unsalted butter, Flour, Salt, ...