BROWN meat with yellow onions in nonstick Dutch oven or large deep nonstick skillet. Add peppers; cook 5 min. or until crisp-tender, stirring occasionally. Stir in garlic and chili powder; cook 1 min.
ADD water and sauce; stir. Bring to boil. Stir in pasta; cover. Simmer 15 min. or just until pasta is tender, stirring occasionally. Stir in corn; cook 3 to 4 min. or until heated through.
TOP with cheese and green onions.