* Red Snapper Fillets should be cut into 8 serving pieces. Place fish fillets in a shallow glass or plastic dish. Mix milk and oregano and pour over the fish. Cover and refrigerate at least 1 hour. Cook and stir onion in the oil in a 10-inch skillet until tender. Stir in the remaining ingredients except the fish. Simmer, uncovered, until thickened, about 15 minutes. Heat the oven to 350 degrees F. Drain the fish fillets and pat dry. Place 1 piece of fish on each of eight 12-inch squares of heavy duty aluminum foil. Spoon some tomato mixture onto the fish. Fold foil over the fish and seal securely. Place the foil packets in an ungreased jelly roll pan, 15 1/2 X 10 1/2 X 1-inch. Bake until fish flakes easily with a fork, about 30 minutes. Serve with snipped fresh cilantro and lemon wedges if desired.