1. Rub roast evenly with 2 Tbsp. olive oil and 1 tsp. pepper. Place roast in a shallow dish or a large zip-top plastic freezer bag; add chopped onions and 1 cup red wine. Cover or seal, and chill at least 8 hours or up to 24 hours, turning once.
2. Remove roast from marinade, reserving marinade. Pat roast dry with paper towels, and sprinkle evenly with 1 1/2 tsp. salt.
3. Brown roast 4 minutes on each side in remaining 1 Tbsp. hot oil in a large heavy-duty roasting pan over medium-high heat. Stir in chicken broth, next 4 ingredients, and reserved marinade; bring to a boil. Remove from heat, and cover with heavy-duty aluminum foil.
4. Bake at 300° for 1 1/2 hours. Turn roast, and bake 1 1/2 to 2 more hours or until meat shreds easily with a fork.
5. Remove and discard bay leaf. Stir in black beans, and cook, stirring occasionally, over medium-low heat 10 minutes or until thoroughly heated.