Fresh garlic and white peppercorns are steeped in rich crè before being strained and ladled over thinly shaved potatoes layer by delicious layer. The gratin is topped with imported Gruyere Cheese; the Perfect finishing touch to this classic gratin that will leave everyone askingfor seconds - and the recipe. Keep frozen until ready to use, the black tray is oven safe but not broiler or toaster oven safe. Preheat oven to 375. Remove lid and place frozen potatoes on a lined baking sheet, cover with foil and bake for one hour. Remove the foil and continue to bake until the top of the gratin begins to brown.