Preheat the oven to 325° F.
Heat olive oil in a large oven safe skillet over medium heat. Add the onion and cook for 5-7 minutes or until softened. Stir in the mustard, ground ginger and tomato paste. Cook for another 2-3 minutes or until fragrant.
Add the apple cider, water, maple syrup, molasses, pinto beans and rosemary stalk. Stir to combine and bring to boil. Cover with a tight fitting lid and transfer to the oven to bake for 45 minutes.
After 45 minutes, remove the lid and bake for another 15 minutes until thick and caramelized. Remove from the oven and stir in the apple cider vinegar. Let sit for 5-10 minutes before serving.
