In 4-quart saucepan, place frozen vegetables and sauce chips. Cover; cook over medium heat about 10 minutes, stirring frequently, just until sauce chips are melted.
Lightly grease 13x9-inch (3-quart) glass baking dish with shortening or cooking spray. Spread bread cubes over bottom of baking dish. Sprinkle with ham. In large bowl, beat eggs and milk; stir in vegetables and cheese sauce. Pour over ham and bread. Cover; refrigerate 4 to 24 hours.
Heat oven to 350°F. Bake strata covered 40 to 50 minutes. Uncover; sprinkle with cheese. Bake about 10 minutes longer or until knife inserted in center comes out clean. Let stand 10 minutes before serving.