1 kg russet potatoes, peeled & quartered 2 lb
125 ml hot milk 1/2 cup
1 ml salt 1/4 tsp
175 ml heavy cream 3/4 cup
125 ml gruyere cheese, shredded 1/2 cup
75 ml parmesan cheese, grated 1/3 cup
Place potatoes in large saucepan and add enough cold water to cover by 1 inch (2.5 cm). Bring to a boil, reduce heat, cover and cook 15 to 20 minutes until tender. Drain the potatoes.
Return the hot potatoes to the pan and mash with a potato masher. Gradually add milk, mashing until smooth. Stir in the salt. Spread the potatoes in a greased shallow 2 quart (2 L) gratin or baking dish and cover to keep warm.
Preheat oven to 450 F (230 C). In a medium bowl; beat cream with an electric mixer on high speed until stiff. Fold in gruyere and 3 tablespoon (45 ml) parmesan cheese. Spread cream over the top of potatoes. Sprinkle remaining parmesan cheese over top.
Bake 12 to 15 minutes, until the potatoes are hot and the top is well browned. Serve at once.
Serves 6