Hearty Chicken Bake

4 cups hot mashed potatoes
1 cup shredded Cheddar cheese
1 can (2.8 ounces) Durkee French Fried Onions
1 1/2 cups cubed cooked chicken
1 package (10 ounces) frozen mixed vegetables, thawed and drained
1 can (10 3/4 ounces) condensed cream of chicken soup
1/4 cup milk
1/2 teaspoon ground mustard
1/4 teaspoon garlic powder
1/4 teaspoon pepper

Preheat oven to 375°. In medium bowl, combine mashed potatoes, 1/2 cup cheese and 1/2 can French Fried Onions, mix thoroughly. Spoon potato mixture into greased 1 1/2 quart casserole. Using back of spoon, spread potatoes across bottom and up sides of dish to form a shell. In large bowl, combine chicken, mixed vegetables, soup, milk and seasonings; pour into potato shell. Bake, uncovered, at 375° for 30 minutes or until heated through. Top with remaining cheese and onions; bake, uncovered, 3 minutes or until onions are golden brown. Let stand 5 minutes before serving.