- 4 ounces sliced bacon, cut into 1⁄2-inch pieces
- 1 onion, chopped
- kosher salt and black pepper
- 1 pound dried navy beans, soaked in water overnight and drained
- 1/2 cup molasses
- 1/4 cup ketchup
- 1 tablespoon dry mustard
- 2 tablespoons cider vinegar
- Heat oven to 300° F. Cook the bacon in a Dutch oven over medium heat, stirring occasionally, until nearly crisp, 5 to 7 minutes. Add the onion, 1 teaspoon salt, and ½ teaspoon pepper and cook, stirring occasionally, until the onion is soft, 4 to 6 minutes more.
- Add the beans, molasses, ketchup, mustard, and 5 cups water to the pot and stir to combine; bring to a boil.
- Cover the pot and transfer to oven. Bake until the liquid is reduced by half, about 2½ hours. Uncover and bake, stirring once, until the cooking liquid is thickened, 1 to 1¼ hours more. Stir in the vinegar and serve.