Heat oven to 350°.
Put the butter in a 13x9x2-inch baking dish; put in the oven to melt the butter.
Meanwhile, in a shallow bowl, combine the egg, water, and lemon juice.
In another shallow bowl, combine the flour, salt, onion powder, and pepper.
Put the crushed crackers or crumbs in another shallow bowl.
Dip each fish fillet in the flour mixture, then dip in the egg mixture. Roll in the crumbs until well coated. Place in the baking dish, gently turning to coat with the melted butter.
Bake for 15 to 20 minutes, or until fish flakes easily with a fork. Time depends on thickness of the fillets.
Calories per serving: 421
Fat per serving: 22.4