HEAT oven to 425F.
COOK bacon in large saucepan on medium heat 5 min. or until crisp. Use slotted spoon to transfer bacon to paper towel. Spoon 2 Tbsp. drippings into small bowl; set aside for later use. Add vegetables to remaining drippings in pan; toss to coat. Spoon into 13x9-inch baking dish.
BAKE 20 min. Meanwhile, return reserved 2 Tbsp. bacon drippings to pan. Stir in flour; cook and stir on medium heat 1 min. Add milk and mustard; bring to boil, stirring frequently. Simmer 1 min or until sauce is slightly thickened. Add Neufchatel; cook 3 min. or until melted, stirring frequently.
REDUCE oven temperature to 350ºF. Sprinkle bacon over roasted vegetables; top with Neufchatel sauce. Mix stuffing mix, parsley and butter; sprinkle over vegetables. Bake 30 min. or until vegetable mixture is hot and bubbly and topping is golden brown.