Potatoes Nana

To clarify butter, melt in small saucepan. Remove from heat; let stand 5 minutes. Using spoon, skim froth and solids from surface. Carefully pour clear melted butter into glass measuring cup, discarding any milky sediment in the saucepan. Preheat oven to 450 F. Drizzle 2 tbsp. clarified butter into bottom of 10-inch diameter oven-proof skillet or flat casserole dish (or quiche pan) with 2-inch high sides. Swirl pan to coat bottom. Placing all potatoes between layers of paper or kitchen towels, dry potatoes well. Arrange half of white potatoes in overlapping circular pattern in prepared pan. Season with salt and pepper. Drizzle with 2 tbsp. clarified butter. Arrange half of sweet potatoes in same fashion over white potatoes. Season with salt and pepper. Drizzle 2 tbsp. clarified butter over this layer. Arrange half of red-skinned potatoes, season, drizzle with butter as before. Repeat layering with remaining potatoes, seasoning and drizzling butter between each layer. Press on potatoes to compact. Cover with foil. Cover and bake potatoes 25 minutes. Uncover and bake until potatoes are tender and top is golden, about 1 hour 15 minutes. Run sharp knife around edge of pan to loosen potatoes. Turn out potato cake onto platter. Sprinkle with herbs and cut into wedges. Notes: A variation on the French classic, pommes Anna, you could also top with shredded cheddar and Monterey Jack cheese after turning out onto plate, before adding herbs. Place back in oven under broiler to melt and put a golden crust on cheese. (Watch very closely to prevent cheese from burning.) Remove from oven, sprinkle with herbs, cut and serve.