01 - Heat olive oil in a large Dutch oven over medium-high heat. Add beef cubes in a single layer and brown on all sides, working in batches if necessary to avoid overcrowding. Transfer browned beef to a plate and set aside.
02 - Add the onion, green bell pepper, carrots, and garlic to the pot. Sauté for 5 to 7 minutes, stirring occasionally, until the vegetables are softened and the onion is translucent.
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 fragrant and the tomato paste darkens slightly.
04 - Return the browned beef and any accumulated juices to the pot. Add the diced tomatoes with their liquid and the beef broth. Stir to combine and bring to a gentle simmer.
05 - Reduce heat to low, cover the Dutch oven, and cook for 1 hour, stirring occasionally to prevent sticking, until the beef is nearly fork-tender.
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 completely tender.
07 - Taste the stew and adjust salt, pepper, and chili heat to your liking. Ladle into bowls and serve hot, garnished with chopped cilantro, sour cream, or shredded cheese if desired.