Put beef, onion & oil in fry pan. Stir to break up meat till it browns. Drain off fat. Put meat mixture in bowl. Put corn, soup, salt & pepper & ketchup in bowl. Stir & mix with meat. Cook noodles, drain & combine with all ingredients. Pour into greased casserole. Sprinkle grated cheese on top. Cover & bake at 350F for 45 min. Remove cover & bake till cheese is bubbly.