Saute onion and green pepper in butter or oil until soft.
Add ground beef to pan and cook until brown. Add garlic.
Sprinkle chili seasoning mix over browned meat. Add tomatoes and beans. Let simmer as long as you wish.
I use canned tomatoes with onions, peppers and garlic added. You can also use canned tomatoes with jalapenos if you like a little more spice. I use one can of chili beans and one can of light red kidney beans but it will work with any combination you wish.