I found this recipe at the Pioneer Woman Cooks. I made it for breakfast on father's day and my whole family really liked it. I have made a few changes in the recipe below.
8 onion roll tops (saved the bottoms to feed the ducks)
1 1/2 cups grated sharp cheddar cheese
1 stick butter
1/2 cup whipped cream cheese
2 cups milk
1/2 tsp dry mustard
1/2 tsp salt
1/2 tsp pepper
1/2 tsp onion powder
5 to 8 shakes of Louisiana hot sauce
Generously butter 9 x 13 baking dish. Place baking dish on foil lined jelly roll pan, as my casserole bubbled over a bit. Tear onion rolls into chunks. Sprinkle with cheddar cheese, then tear cream cheese into small piece and place over the top. Cut 1 stick butter into thin pats and place over the top. Mix remaining ingredients and pour over the top of the dish. Cover and refrigerate overnight. The next morning, bake at 325 degrees, covered, for 45 minutes. Then remove foil and continue baking at 350 for 10-15 minutes.