- 2 tablespoons vegetable oil
- 1 cup chopped white onion
- 1 large jalapeño chili with seeds, cut lengthwise in half
- 1 tablespoon dried oregano (preferably Mexican)
- 1 pound dried pinto beans, rinsed
- 2 tablespoons (packed) dark brown sugar
Heat oil in heavy large pot over medium-high heat. Add onion; sauté until translucent, about 3 minutes. Add garlic, chili, oregano, and cumin; sauté 1 minute. Add 9 1/2 cups water and beans. Bring to boil. Reduce heat to medium-low, cover, and simmer 1 hour.
Discard chili. Add sugar and salt to bean mixture. Simmer uncovered over medium heat until beans are tender and almost all liquid has evaporated, about 1 hour longer. Remove from heat. Using potato masher, coarsely mash most of beans. Season with additional salt, if desired. DO AHEAD: Can be prepared 1 day ahead. Cool slightly. Refrigerate until cold, then cover and keep chilled. Rewarm in nonstick saucepan over medium heat, stirring frequently.