Golden Grouper - cooking recipe

Ingredients

8 grouper fillets (or any firm fish, like mahi mahi for example)
Sauce
4 ounces butter
1 -2 onion, chopped
1 -2 lemon, juice of
2 -4 tablespoons spicy brown mustard
salt and pepper

Preparation

Preheat oven to 350 degrees.
Melt butter in sauce pan. Add onions and sautee until soft. Add remaining sauce ingredients.
Place fish in shallow baking dish. Spoon sauce over fillets. Bake for about 15 minutes, or until done. Can also grill, basting with sauce as needed.