Colombian Black Beef

Name: Colombian Black Beef
Cuisine: American, Latin American
Ingredients: 2 lbs (900 g) beef eye of round or rump roast; 2 cloves garlic, minced; 1 medium onion, finely chopped; 1 tsp ground cumin; 1 tsp black pepper; 2 tsp salt; 1/4 cup Worcestershire sauce; 1/2 cup beer (dark beer recommended); 3 tbsp vegetable oil; 1/4 cup brown sugar; 1 cup cola; 1 cup beef stock; 2 tbsp tomato paste; 1/4 cup raisins; 1 bay leaf; White rice or coconut rice; Fried plantains or avocado (optional)