Heat oil in a deep fryer or deep heavy skillet to 365°F (185°C). Warm gravy in saucepan or microwave. Place the fries into the hot oil, and cook until light brown, about 5 minutes. Remove to a paper towel lined plate to drain. Place the fries on a serving platter, and sprinkle the cheese over them. Ladle gravy over the fries and cheese, and serve immediately.