Black bean and sweet potato chili (with beer)

This was great--nice flavors. I got this from my daughter who got it from her sister-in-law ;-).


1 T olive oil
1 medium yellow onion, diced
1 orange pepper, diced
1 red pepper, diced
2 cloves garlic, minced
1 teaspoon cumin
2 teaspoons chili powder
One 15-ounce can diced tomatoes
Three 15-ounce cans black beans, rinsed and drained (I used 2 black, 1 red
bean)
1 small chipotle chile pepper in adobo sauce, minced (I omitted)
¼ cup chopped cilantro stems (I only had dried cilantro on hand)
Kosher salt
1 bottle dark beer (I used some Gluten Free Beer)
1 pound sweet potatoes, peeled and cut into 1-inch cubes
¼ cup chopped cilantro leaves
1/2 lime (optional)
sour cream (optional)

Heat oil in large Dutch oven or heavy-lidded saucepan over medium heat. Saute onion and peppers until soft and beginning to caramelize, 5-8 minutes. Add garlic, cumin, and chili powder and continue to sauté until very fragrant, about 2 minutes. Stir in tomatoes, beans, chipotle, cilantro stems, and 1 teaspoon salt. Turn heat to high, and pour in beer. Simmer for 10 minutes, then add sweet potatoes. Cook for about 20 more minutes or until potatoes are done.