In a Dutch oven, cover the navy beans with water.
16 ounces navy beans
Bring to a boil, then turn off the heat and cover. Let soak for 1 hour. Then drain off the water.
Return the pot to medium heat and cook the pork belly until the fat begins to render.
¼ pound pork belly
Add the drained beans back to the pot. Also add the salt, pepper, tomato sauce, molasses, dry mustard, Worcestershire sauce, baking soda, and water.
1 Tablespoon kosher salt, 1 teaspoon black pepper, 8 ounces tomato sauce, ⅓ cup molasses, 1½ teaspoons dry mustard, 1 Tablespoon Worcestershire sauce, ¼ teaspoon baking soda, 4 cups water
Bring to a boil, then reduce the heat to a simmer, stirring occasionally, until the beans are tender and the sauce has thickened.
Thickening will take about 2 hours. Add small amounts of water (1-2 tablespoons) as needed to keep the beans from drying out before they are fully tender.
Stir in apple cider vinegar and serve as is, or use as a base for baked beans.
3 Tablespoons apple cider vinegar