My Favorite Crock Pot Roast Beef

3-4 pound rump roast or other pot roast
1 tablespoon shortening
1 teaspoon salt
1/4 teaspoon pepper
1 pound peeled pearl onions
1 cup sliced mushrooms
1/2 cup beef broth
1 cup red wine (optional)
Dash of tomato paste

Brown meat in hot shortening in a skillet. Put half onions and mushrooms in the bottom of a slow cooker. Salt and pepper meat and place in slow cooker. Add remaining vegetables and liquids.  Cover and cook on low for 10-12 hours or high 5-6 hours.
Serve with boiled or roasted new potatoes, or mashed potatoes, and haricots verts. A simple green salad (thinly sliced radishes are a nice addition) with vinaigrette and old fashioned dinner rolls make a delicious and satisfying dinner.