1 pound dried navy beans, soaked overnight in cold water and drained
4 cups water
One 12-ounce bottle dark beer
1 teaspoon dried oregano
1 teaspoon dried thyme
1 bay leaf
1/2 cup dark brown sugar
1/3 cup molasses
1/3 cup ketchup
2 tablespoons Dijon mustard
Kosher salt and fresh ground pepper
In a medium enameled cast-iron casserole, cook the bacon over moderately high heat until the fat is rendered and the strips are beginning to brown, about 5 minutes. Reduce the heat to moderately low. Add the onion and garlic and cook until softened, about 5 minutes. Stir in the cider vinegar, whole-grain mustard, Worcestershire sauce and tomato paste and scrape up any browned bits from the bottom of the casserole.
Add the drained beans, water and beer; the beans should be covered by an inch of liquid so add more water if necessary. Stir in the oregano, thyme and bay leaf and bring to a boil. Cover and simmer over low heat until the beans are almost tender, about 2 hours and 30 minutes.
Stir the brown sugar, molasses, ketchup and Dijon mustard to the beans. Season with salt and pepper. Cover partially and cook until the beans are very tender and the cooking liquid is thickened, about 1 hour longer. Discard the bay leaf. Serve the beans hot or at room temperature.