In small bowl combine stuffing ingredients, mix well. In seperate bowl mix mustard ingredients. make 12-14 deep slits in steak to form pockets, careful not to cut through to the bottom. Stuff each fully with stuffing, using it all. Rub the surface of the steak with the seasoned mustard. Cover well and refrigerate overnight, untill ready to cook.

Place steak, stuffing side up, and the accumulated juices in a heavy ovenproof 8 qt dutch oven, so steak lies as flat as possible. Sprinkle the onion and peppers on top and pour stock around the meat, only a little on. Cover and bake 300 for 1 hour. Remove lid, push onion and pepper off sides into liquid, continue baking uncovered just until tender and juices run clear, about 1 hr. 45 minutes more depending on thickness of meat.

Remove pan from oven and transfer steak to a platter. Spoon our 3 tablespoons juices and mix with the flour. Stir in to juices until well blended. Bring to a boil, then simmer until thickened, about 10 minutes stirring frequently. Serve with rice. SERVES 8-10