- 1 tablespoon olive oil
- 1 medium onion, diced
- 4 cloves garlic, minced
- 4 teaspoons mustard powder
- 2 1/2 teaspoons chili powder
- 2 teaspoons ground cumin
- 1 can (14 1/2 ounces) whole tomatoes, with juice
- 1/4 to 1/3 cup packed light-brown sugar
- 4 cans (14 1/2 ounces each) pinto beans, drained and rinsed
- 1 tablespoon cider vinegar
- Salt and pepper
In a 5-quart saucepan, heat oil over medium-high. Cook onion until translucent, stirring often, 3 minutes. Add garlic, mustard and chili powders, cumin, tomatoes, brown sugar, beans, and 3 cups water.
Bring to a boil; reduce heat to medium-low. Cover; simmer, stirring occasionally, 50 minutes. Uncover; cook until thick, about 10 minutes more. Stir in vinegar; season with salt and pepper.