1. Preheat oven to 425 degrees Fahrenheit.
2. In a shallow dish, combine bread crumbs, dry mustard, salt, and pepper.
3. Dip hens into melted margarine and roll in the bread crumb mixture.
4. Place hens in a greased nine- by 13-inch baking dish. Bake for 30 minutes, basting once with remaining margarine.