Crock Pot Mexican Beef

1 1/2 lb. round steak, cut in bite size pieces
1/4 tsp. pepper
1/2 tsp. garlic salt
1 tbsp. chili powder
1 tbsp. prepared mustard
1 chopped onion
1 beef bouillon cube, crushed
1 (16 oz.) can tomatoes, cut up
1 (16 oz.) can kidney beans, drained ( I plan on using black beans)

Mix meat, salt, pepper, chili powder and mustard in pot. Cover with onion, bouillon cube, and tomatoes. Top with beans. Cover and cook on low 6-8 hours. Mix and serve with rice.