Heat Half The Butter In A 1-Quart Saucepan Over Medium Heat Until Melted. Remove The Saucepan From The Heat. Add The Stuffing And Parsley And Mix Lightly. Heat The Remaining Butter In A 10-Inch Skillet Over Medium Heat. Add The Onions And Cook Until Tender, Stirring Occasionally. Stir The Soup, Milk And Peas In The Skillet. Spoon The Soup Mixture Into A 2-Quart Shallow Baking Dish. Sprinkle With The Cheese And The Stuffing Mixture. Bake At 350 Degrees F For 30 Minutes Or Until The Mixture Is Hot And Bubbling.