Wash the artichokes and cut off all the leaves to expose the bottom. Carve the choke out with a grapefruit knife, or teaspoon. Cut each bottom in quarters. In a flameproof serving dish, melt the butter and oil and brown the pork belly and chopped onions. Add the tomatoes, salt and pepper and cook for 3 minutes stirring often. Place the artichoke bottoms in the serving dish and add 2 cups chicken stock. Taste for seasoning, add the bouquet garni and cook over high heat until very little liquid is left. This dish can accompany roast meat.
