Toss vegetables with 1 Tbsp. (3 tsp.) pasta sauce. Spread onto bottom of 11x8-inch baking dish sprayed with cooking spray. Top with chicken placed in single layer over vegetable mixture. Spread chicken with remaining pesto sauce.
Bake 18 to 20 min. or until heated through. About 10 min. before chicken and vegetables are heated through, prepare potatoes as directed on package.
Heat gravy as directed on label.
Place potatoes and chicken on serving plates; drizzle with gravy. Serve with mixed vegetables.