Beef Enchiladas

This is my son's favorite dish. I must admit that every once in a while, I do cheat and buy Ole El Paso brand frozen burritos to make this dish. I know... Enchiladas are corn tortillas, but Elliott doesn't like the corn. I use flour... So, if you want to get technical, these are burritos cooked in enchilada sauce and cheese. Either way, they make my son happy and that's what I'm after!

1 pkg. 8-inch tortillas
1 1/2 lb. hamburger
1 med onion, chopped
1 -16 oz can refried beans
1 - 4 oz can chopped mild green chiles
2 cups shredded Monterey Jack cheese
1 cup shredded Cheddar cheese
1 1/2 cups milk
3 tsp cornstarch
1 -10 oz can mild enchilada sauce

Arrange tortillas on a plate; cover with a damp paper towel. Microwave for 30 seconds at the time until soft and hot.  Cook ground beef and onion, drain.  Add refried beans, green chiles with liquid, and 1 cup of shredded Monterey Jack cheese.  Heat until blended, remove from heat.  Spoon about 1/3 cup meat mixture in lengthwise strip on center of each tortilla; roll up jelly roll fashion, place seam side down in large baking pan.  Stir milk and cornstarch until smooth, cook, stirring, until mixture boils and thickens slightly.  Add enchilada sauce and remaining 1 cup Monterey Jack cheese.  Cook, stirring until smooth.  Pour over tortillas, sprinkle cheddar cheese over top and bake at 350 degrees approximately 25 to 30 minutes.  Serve as is or can be garnished with tomato slices, shredded lettuce, black olives and sour cream.