Brown ground beef and onion in fry pan. Drain fat .
Open enchilida sauce and heat in a smaller fry pan. Grab a cookie sheet dip flour tortillas in sauce place one at a time on cookie sheet. with slotted spoon scoop ground beef mixture inside tortilla a grated cheese and roll up. repeat .till all tortillas are on pan .
pour left over sauce on enchillidas and sprinkle with cheese. pre heat oven to 350 heat in oven until cheese is melted. 5-10 minutes.