Onion Beef Au Jus

1 boneless beef rump roast (4 lbs.)
2 tbsp. canola oil
2 lg. sweet onions, cut into 1/4-inch slices
6 tbsp. butter, softened, divided
5 c. water
1/2 c. soy sauce
1 envelope onion soup mix
1 garlic clove, minced
1 tsp. browning sauce, optional
1 loaf French bread
1 c. Swiss cheese, shredded

1. In a Dutch oven, over medium-high heat, brown roast on all sides in oil; drain.
2. In a large skillet, saute onions in 2 tbsp. butter until tender. Add the water, soy sauce, soup mix, garlic and browning sauce if desired. Pour over roast.
3. Cover and bake at 325 F for 2 1/2 hours or until meat is tender.
4. Let stand 10 minutes before slicing. Return meat to pan juices.
5. Slice bread in half lengthwise; cut into 3-inch sections. Spread remaining butter over bread. Place on a baking sheet. Broil 4-6 inches from the heat for 2-3 minutes or until golden brown.
6. Top with beef and onions; sprinkle with cheese. Broil 4-6 inches from heat for 1-2 minutes or until cheese is melted. Serve with pan juices.