Cook beef according to package directions. Spoon beef into a lightly greased 11"x7" baking pan. Top with corn and peas; set aside.

Cook potatoes according to package directions; spoon potatoes into a bowl. Add cream cheese, butter and garlic powder; beat at medium speed with an electric mixer until smooth. Spread potato mixture over vegetables; sprinkle with cheese.

Bake, uncovered, at 350 degrees for 15 minutes or until thoroughly heated.