Heat the oil in a large skillet or pot over medium heat.
Add the diced onion and cook for about 5 minutes, until it becomes soft and translucent.
Add the cooked pinto beans, water, apple cider vinegar, maple syrup, dill, Dijon mustard, salt, pepper, and ground cloves to the pot.
Stir everything together until well combined.
Bring the mixture to a boil, then reduce the heat to low.
Cover the pot and let it simmer for 45 to 60 minutes, stirring occasionally. The beans are ready when the liquid has thickened into a rich, well-bodied sauce.
While pinto beans are classic, this recipe also works beautifully with navy, cannellini, or even black beans.