Chicken Breasts Cacciatore
["3 chicken breasts, split (about 12 oz each)", "1 Bermuda onion, cut in 6 slices", "1 envelope (1 1/2 oz) spaghetti sauce mix", "1 can (1 lb.) tomatoes"]
["Brown breasts in a large nonstick skillet: arrange in single layer in an 8 cup shallow casserole. Top each breast with an onion slice."]
["chicken breasts", "Bermuda onion", "spaghetti sauce mix", "tomatoes"]