Divine Au Gratin Potato Recipe

I tried this out for Thanksgiving, and it was was so delish - sorry, Rachael - that I've been bragging about it for days. Several people asked for the recipe, so here you go.

Sweet Onion Potatoes Au Gratin
(original by Rachael Ray, adaptation by moi)
  • 2 tablespoons butter (plus 1 stick butter)
  • 1 large or 2 medium sweet onions, such as Vidalia, thinly sliced
  • Salt and freshly ground black pepper
  • 1/2 teaspoon ground thyme
  • 1 bay leaf, dried
  • 48-52 oz Honey Gold fingerling potatoes
  • 2/3 cup heavy cream
  • 3/4 cup grated Parmigiano Reggiano cheese (I prefer the four cheese blend from Publix with Asiago)
  • 1/2 pound brick Gruyère, shredded

Heat a small skillet with 2 tablespoons of butter over medium heat. Add the onions and season with salt (I like course ground sea salt), the ground thyme and bay leaf and cook until very soft and sweet and lightly caramelized, 20 minutes. Season with salt and pepper, to taste, and discard the bay leaf.

While the onions cook, put the potatoes (don't bother to skin) in a medium size pot and cover with water. Bring to a boil, then salt the water and cook until tender, 20 minutes. Drain and return the potatoes to the hot pot. Mash the potatoes with the cream and Parmigiano Reggiano and season with salt and pepper, to taste. Add stick of butter for perfect creamy consistency.

Pre-heat the broiler.

Arrange the mashed potatoes in individual gratin dishes or one shallow casserole dish. Top the potatoes with the onions and Gruyère cheese. Place the dish(es) on a sheet pan and brown under a hot broiler until bubbly, about 2 minutes. Remove from the oven and serve hot.