Replace turkey with 4 kinds of beans to make it vegetarian.

1 tablespoon olive oil
1 onion, chopped
1 green bell pepper, chopped
2 cloves garlic, chopped
1/2 pound ground turkey (preferably dark meat)
2 tablespoon tomato paste
1 teaspoon ground cumin
1/2 teaspoon ground chipotle chili pepper or 2 teaspoons chili powder
1 28-ounce can diced tomatoes
2 15-ounce cans kidney beans, rinsed
kosher salt and black pepper
1/4 cup reduced-fat sour cream
cilantro sprigs, for serving