Fry burger, drain and return back to pan. Add onion and cook till onion is almost soft. Add corn, sour cream and miracle whip. Mixture should not be dry. May add extra sour cream and miracle whip if needed.
Put into casserole dish. May need 2 dishes as this makes a lot. Fill dishes 3/4 full. Add crunched doritos on top. Top off with shredded cheese. Cook 5 minutes.
Optional: After cooking for 5 minutes I like to put dishes under broiler till top of cheese is dark and bubbly. Watch so it doesn't burn. Yummmo!