Cook sausage in a medium saute pan until golden brown and fat has rendered. Remove the sausage with a slotted spoon to a plate lined with paper towels. Add the onion and carrot to the pan and cook until soft. Add the garlic and cook for 1 minute.
Place the beans in a large bowl, stir in the cooked onion mixture, rum, honey, molasses, sugar, and cooked chorizo. Season with salt and pepper, to taste. Transfer the mixture to a casserole or baking dish and pour 3 cups of the stock over. Bake the beans, covered, for 20 minutes. Check to see if the mixture is dry and add more stock, if needed. Continue baking an additional 20 minutes. Uncover and bake for 15 minutes, remove from the oven, and fold in the cilantro, if using. Let sit for 10 minutes before serving.