Heat oven to 375°F.
Place vegetables in colander in sink. Cook Macaroni as directed on package; pour over vegetables to drain macaroni and thaw vegetables. Return to saucepan.
Stir in Cheese Sauce, milk and dressing. Add tuna and 1/2 cup Cheddar; mix well. Spoon into 2-qt. casserole; cover.
Bake 35 min. or until heated through. Top with remaining Cheddar; bake 3 to 4 min. or until melted.
Substitute 1 lb. extra-lean ground beef, cooked and drained, for the tuna.
Assemble casserole as directed. Refrigerate up to 24 hours. When ready to serve, bake, covered, at 375°F for 40 to 45 min. or until heated through. Top with remaining cheese; continue as directed.
Prepare using 2 (6-oz.) cans tuna.
Nutrition Information Per Serving (tuna, 2% version): 420 calories, 11g total fat, 5g saturated fat, 50mg cholesterol, 1330mg sodium, 48g carbohydrate, 4g dietary fiber, 9g sugars, 32g protein, 45%DV vitamin A, 60%DV vitamin C, 60%DV calcium, 15%DV iron.
Exchange: 3 Starch, 1 Vegetable, 3 Meat (VL), 1 Fat