01 - Heat olive oil in a large Dutch oven over medium-high heat. Add beef cubes in a single layer, browning on all sides. Work in batches if needed to avoid overcrowding. Remove browned beef and set aside.
02 - Add the chopped onion, diced green bell pepper, sliced carrots, and minced garlic to the pot. Sauté for 5 to 7 minutes until the vegetables are softened and fragrant.
03 - Stir in the tomato paste, chili powder, ground cumin, smoked paprika, cayenne pepper, salt, and black pepper. Cook for 2 minutes, stirring constantly, until the spices are deeply fragrant and the tomato paste darkens slightly.
04 - Return the browned beef to the pot. Pour in the diced tomatoes and beef broth, stirring to combine. Bring the mixture to a steady simmer.
05 - Reduce the heat to low, cover the Dutch oven, and cook for 1 hour. Stir occasionally to prevent sticking and ensure even cooking.
06 - Stir in the drained kidney beans and black beans. Continue simmering uncovered for 20 to 30 minutes until the stew has thickened and the beef is fork-tender.
07 - Taste the stew and adjust salt, pepper, and spices as needed. Ladle into bowls and serve hot, garnished with chopped cilantro, sour cream, or shredded cheese if desired.