Rinse the dried pinto beans under cold water.
Soak the beans in water overnight.
Drain and rinse the soaked beans.
In a large pot, add the beans and 4 cups of fresh water.
Bring the water to a boil over medium-high heat.
Add chopped onion, minced garlic, and diced bell pepper.
Stir in cumin and chili powder.
Reduce heat to low, cover, and simmer for about 1 to 1.5 hours.
Season with salt and pepper.
Serve hot, garnished with fresh cilantro.