1/4 cup chopped onion
1/4 cup chopped celery
1/4 cup chopped green bell pepper
2 tablespoons butter, melted
3/4 teaspoon pepper
3/4 teaspoon minced garlic
1/2 teaspoon dry mustard
1/2 teaspoon cayenne pepper
4 pounds beef sirloin roast
Preheat oven to 300*F (150*C)
In a small bowl combine finely chopped onions, finely chopped celery, chopped green bell peppers, melted butter, pepper, minced garlic clove, dry mustard, and cayenne pepper. Mix well.
Place a beef sirloin roast in a large roasting pan, fat side up. Make 6 to 12 deep slits in the meat to form pockets down to a depth of about 1/2 inch from the bottom; but do not cut through. Fill the pockets with the vegetable mixture.
Bake uncovered in the oven for about 3 hours, or until a meat thermometer reads about 160*F. For rarer roast, cook until the thermometer reads 140*F.
Makes 6 servings.