Ingredients

• 1 lb dried navy beans (2 1/4 cups)
• 1 (1/4-lb) piece salt pork (rind discarded)
• 4 1/2 cups water
• 1 large onion, finely chopped (about 2 cups)
• 2 chopped garlic cloves
• 1/2 cup Grade B maple syrup
• 1 tablespoon dry English mustard (preferably Colman's)
• 1 teaspoon freshly ground black pepper

Instructions

1. Pick over and rinse 1 lb dried navy beans (2 1/4 cups). Soak in cold water to cover by 2 inches at least 8 hours. Alternatively, quick-soak beans (see cooks' note, below). Drain.
2. Put oven rack in middle position and preheat oven to 350°F. Rinse and pat dry 1 (1/4-lb) piece salt pork (rind discarded), then cut into 3 pieces.
3. Put beans and pork in an ovenproof 3-quart heavy pot with a lid. Add 4 1/2 cups water, 1 large onion (finely chopped; about 2 cups), 2 chopped garlic cloves, 1/2 cup Grade B maple syrup, 1 tablespoon dry English mustard (preferably Colman's), and 1 teaspoon freshly ground black pepper and stir to combine. Cover pot and bake until beans are just tender, 3 to 4 hours.
4. Reduce oven temperature to 325°F. Remove lid. Bake beans, stirring occasionally, until most of liquid is absorbed but beans are still saucy, 1 to 1 1/2 hours more. Remove from oven. Stir in 1 tablespoon cider vinegar and 1 teaspoon salt or more to taste.