Steps:

• Place ground beef into a soup pot over medium heat, and cook and stir until the meat is browned, breaking it up into crumbles as it cooks, about 10 minutes. Stir in onion and garlic, and cook until the onion is translucent, about 5 more minutes. Drain excess grease if necessary, and sprinkle the meat with taco seasoning mix; cook the meat with the seasoning for 1 or 2 more minutes.
• Pour in the chili-flavored tomatoes, chili beans, tomato sauce, and diced green chilies, and stir to combine; simmer for 30 minutes to blend flavors.

Steps:

• Heat a large pot over medium-high heat. Cook and stir beef, onion, and garlic together in the hot skillet until beef is completely browned, 5 to 7 minutes; drain and discard grease.
• Stir diced tomatoes, kidney beans, pinto beans, black beans, crushed tomatoes, tomato paste, chili seasoning mix, salt, and black pepper with the beef mixture; bring to a boil, reduce heat to medium-low, place a cover on the pot, and simmer the chili until the beans are tender, about 20 minutes.