Over medium heat, sauté scallops in 2 tablespoons of the butter. Remove scallops from skillet and set aside.
Add the remaining butter to the skillet. Over medium heat, sauté the onion, and mushrooms for about 4 minutes.
Add wine, dressing, cheese and scallops and heat for 1 minute.
Spoon mixture into a lightly greased casserole. Broil 4 inches from heat for
2 to 4 minutes