Cheesy Chicken and Corn Casserole

I found this recipe on Three on Food and thought it looked like something we would all like. I reduced the butter by A LOT and thought it was really good. Mike especially loved it...even with all the corn :-)!

Ingredients:
1 Box Yellow Rice (I used a 10oz. bag)
1 Stick Margarine (I used 2 T., 1 in rice and 1 for chicken)
1/2 onion, chopped
1 Can Cream Of Chicken Soup (I used 98% FF)
1-2 Cups shredded, cooked chicken (I used 1 breast because I'm getting low on my canned chicken)
1 can Whole Kernel Corn, drained
1 1/2 Cups Cheddar Cheese

Directions:
Cook rice according to package directions.
Fry your chicken in some butter and set aside (I seasoned with salt, pepper and garlic salt).
Saute your onion in the same skillet as the chicken bits.
Add rice and all other ingredients, except for 1/2 C of cheese, into a bowl and stir until well combined.
Spoon into casserole dish and top with remaining cheese.
Bake at 350 degrees for about 30 min, or until bubbly.