2 tablespoons olive or canola oil
1 medium yellow onion, chopped
1 large carrot, chopped
1 stalk celery, chopped
1 medium green bell pepper, cored, seeded and chopped
1 medium red bell pepper, cored, seeded and chopped
3 cloves garlic, finely chopped
1 tablespoon dried oregano
1 tablespoon finely chopped chipotles in adobo
2 teaspoons ground cumin
1 tablespoon chili powder
1 1/2 teaspoon salt
1 (28 ounce) can diced tomatoes, with their liquid
3 cups cooked red kidney beans, drained
1 1/2 cup cooked black beans, drained