Mix together corn, onion, pepper, chilis (opt.) and dry macaroni. Slice butter into the mixture along with the cheese. Add milk. Add seasoning to your liking. Pour into a greased casserole dish with a lid.
Cover and bake at 350 degrees for 30 minutes. Remove lid and stir. Add more milk if mixture seems dry.
Continue baking, uncovered, for another 30 minutes until top is a little browned and macaroni is tender. If mixture seems too dry, add more milk. Some corn has more liquid than others. Let set a few minutes, covered, and serve.