Spaghetti with Mushroom Bolognese
In a small bowl, cover the porcini with 1 cup of boiling water; soak until softened, about 30 minutes. Finely chop the porcini, discarding any tough bits. Pour off and reserve 1/2 cup of the soaking liquid. In a large enameled cast-iron casserole, heat 2 tablespoons of the oil. Add the onion and carrots and