Clean the mushrooms well, wash them with a damp cloth and cut them into thin slices.

Chop the onion with the garlic.

Heat a terracotta casserole for a few minutes, then add the oil and the chopped mixture and sauté over moderate heat until the onion is wilted.

Pass the tomatoes through a vegetable mill and add them, with the mushrooms, to the rest.

Add a pinch of spices, the pine nuts, pepper and salt; mix, cover and cook over very low heat for an hour, stirring often.