Brown the ground beef, chopped onion, salt and pepper in a skillet.  Once browned, drain and add 1 tablespoon of the chili powder, mix thoroughly.

In a large pot, add the chili beans. Add the meat mixture and diced tomatoes to the beans and mix well.  Cook over medium heat until it starts to simmer. Turn heat down to low and simmer for 30 minutes.

After 30 minutes of simmering, add more chili powder to your taste. If you added more chili powder, continue to simmer for an additional 15 minutes.

Serve warm, with a dollop of sour cream and a sprinkle of cheese.  Enjoy!