How to Make It
Heat the olive oil in a large saucepan. Add the garlic, celery and onion and cook over low heat, stirring, until softened, about 8 minutes. Add the beans and stock and bring to a boil. Reduce the heat to low, cover partially and simmer until the beans are almost tender, 45 minutes to 1 hour. Stir in the tomatoes, ketchup, brown sugar, vinegar, mustard, basil, rosemary, cumin and paprika. Simmer over moderately low heat until the beans are very tender and the sauce is thick, about 30 minutes longer. Season with salt and pepper.
Preheat the oven to 350°. Melt the tablespoon of butter in a large, deep ovenproof skillet. Add the sausages and brown over moderately high heat, about 1 minute per side. Transfer the sausages to a plate and pour off any excess oil from the skillet. Add the beans to the pan, then nestle the sausages in the beans. Butter the bread on both sides and season with salt and pepper. Set the bread on the beans and sprinkle the Cheddar over the bread. Bake in the center of the oven for about 20 minutes, or until the cheese is browned and the bread is crisp. Serve at once.