Place the rinsed and soaked wheat berries in a pan with 3½ cups cold water. Boil for 15 minutes remove from heat. The berries will not be fully cooked; this is a pre-step only. Preheat oven to 300°.
Oil casserole dish with olive oil, then rub the garlic over the entire surface. Combine drained beans, wheat berries and onions. In a separate bowl, mix the brown sugar, Worcestershire sauce, molasses, chilies, mustard curry powder and rum. Mix well and pour over the bean and berry mixture. Add 1 cup of tomato juice, mix well. Transfer the mixture to the casserole dish. Cover and bake for 6 hours. Add tomato juice to the casserole as the beans dry out. If all of the juice is used up, keep the beans moist with broth.