I make this very often. It's one of the first recipes I made when I got married and I'm still making it. It's great for using up left over chicken and very easy to make. This is a favorite in our house!
Chop the onion and saute in butter until tender in a large skillet.
Combine all the rest of the ingredients in with the onions except the cheese and biscuits.
Spoon mixture into prepared dish and bake for 15 minutes.
Remove from oven.
Arrange biscuits on top and sprinkle cheese over everything.
Bake until biscuits are golden brown and sauce is bubbly. (About 20 minutes longer).
Helpful tip: If you are in a hurry, use biscuits that are already cooked. Just set them in the mixture and cook for about 5 or 10 minutes instead of 20. They will soften and you can never tell the difference!