01 - In a large pot over medium-high heat, cook the ground beef and diced onion until the beef is browned and the onion is translucent. Drain excess fat if necessary.
02 - Stir in the kidney beans, diced tomatoes, chili powder, ground cumin, salt, and black pepper. Mix thoroughly to combine all ingredients.
03 - Reduce the heat to low. Cover and simmer for 30 minutes, stirring occasionally to prevent sticking. Adjust seasoning as needed.