1In large bowl, mix potatoes, onions, salt and pepper. Coat 10-inch nonstick skillet with slanted side with 1 tablespoon of the oil; heat over medium heat. Spread 2 1/2 cups of the potato mixture evenly over bottom of skillet; press down with back of broad spatula. Top with cheese to within 1 inch of edge. Spread remaining potatoes over cheese; press down with back of broad spatula.
2Cook over medium heat 15 minutes or until potatoes are well browned and crisp. Loosen edge of potatoes with spatula. Place heatproof plate upside down over skillet; carefully turn skillet upside down over plate to remove potatoes.
3In same skillet, heat remaining 1 tablespoon oil over medium heat. Slide potatoes from plate into skillet so uncooked side is down. Cook about 10 minutes or until potatoes are well browned and tender. Slide onto serving plate. Cut into wedges.