On your oven, set it to preheat to 350 degrees F. Take a medium sized skilled over a medium high heat, and cook the beef and onion. Cook it until the beef is evenly browned, and the onion is tender.

Now you want to prepare the enchilada sauce. Use package directions for this. Pour 1/4 cup of the sauce into the bottom of a baking dish that is 9x13.

Take your flour tortillas, and on each one, place an equal portion of the ground beef mixture you made, and about 1 ounce of cheddar cheese. Reserve about 1/2 cup of the cheese. Now you want to tightly roll these tortillas and place them seam side down in the baking dish.

Pour your remaining sauce over the top of your enchiladas, and be sure to sprinkle the remaining cheese and olives. Bake this in the preheated oven for about 20 minutes. Be sure to check to see if the sauce is bubbly and the cheese is thoroughly melted, in case it needs to come out of the oven sooner.