Heat oven to 375°. Cook beef, onion, celery and garlic in 12-inch skillet over medium-high heat 8 to 10 minutes, stirring occasionally, until beef is brown; drain.
Stir soup, corn, picante, chili powder and pepper into beef mixture. Spoon into ungreased 2 1/2-quart casserole. Top with frozen potato nuggets.
Bake uncovered 40 minutes. Sprinkle with cheese. Bake 5 to 10 minutes or until bubbly and cheese is melted.