Boil macaroni according to package directions; set cheese packet aside.
Meanwhile, in a large skillet brown the beef and onion until meat is no longer pink and onions are tender; drain.
Add the roasted red pepper, soup, water, ketchup, mustard, salt, chili powder, oregano, cumin, and pepper to the meat. Bring to a boil. Reduce heat; simmer, uncovered, for 4 minutes.
Drain macaroni; add to the beef mixture. Then stir in the corn, cheese, contents of reserved cheese packet, butter and milk. Cook over medium heat until heated through.
Notes
**note: fresh green or red pepper may be substituted. If using fresh add to the recipe along with the onion in step #2.