b'TO PREPARE THE PEPERONATA SAUCE:In a large, deep saut pan, heat the oil over medium-high heat, then add the garlic, red pepper flakes, onion and bell peppers. Saut until soft, about 5 minutes. Increase the heat slightly. Add the prosciutto or ham, salt and pepper. Saut about 2 to 3 minutes. Add the Marsala wine. Stir well and cook until the liquid is reduced by half. Stir in the parsley and thyme.Add the chicken stock. Bring to a boil and then simmer for about 20 minutes.Add the cream. Stir and continue to simmer for about another 10 to 15 minutes. The sauce is the proper consistency when it coats the back of a spoon.TO SERVE:Place the sauce on each serving plate. Top with a tuna steak and sprinkle with parsley. Serve immediately.'