Three-Cheese Potato Souffle
["4 c. mashed potatoes (without added milk or butter)", "1 c. fat-free milk", "1 c. (4 oz.) shredded reduced-fat cheddar cheese", "2/3 c. shredded reduced-fat Swiss cheese", "1/3 c. shredded Parmesan cheese", "1/3 c. chopped green onions", "1 small onion, chopped", "1-1/4 tsp. salt", "1/4 tsp. pepper", "4 eggs, separated"]
["In a large bowl, combine the first nine ingredients. Beat egg yolks; stir into potato mixture. In a small mixing bowl, beat egg whites until stiff peaks form; gently fold into potato mixture. Transfer to a 2-qt. souffle dish coated with nonstick cooking spray. Bake, uncovered, at 375\u00b0 for 40 - 45 minutes or until golden. Serve immediately."]
["potatoes", "milk", "cheddar cheese", "shredded reduced-fat", "Parmesan cheese", "green onions", "onion", "salt", "pepper", "eggs"]