Sweet Onion Potatoes Au Gratin
- 2 Tbl. Butter
- 1 large or 2 medium sweet onions, such as Vidalia, thinly sliced
- salt and pepper
- 1/2 tsp. ground thyme or dried if ground isn't available
- 1 baly leaf, fresh or dried
- 2 lb. baby Yukon Gold potatoes or fingerling potatoes
- 1/2 to 2/3 cup cream
- 1/2 cup grated Parmigiano-Reggiano cheese
- 1/2 lb. grated Gruyere or other Swiss cheese
Heat butter in a skillet over medium heat.
Add onions. Season with salt, pepper, thyme and bay leaf. Cook until very soft, sweet and lightly caramelized, about 20 minutes.
Remove bay leaf.
While onions cook, place potatoes in pot and cover with water. Bring to a boil, salt the water, and cook until, 12-15 minutes. Drain and return potatoes to pot.
Mash the potatoes with cream, season with salt and pepper, and mix in the Parmigiano cheese.
Preheat broiler. Arrange the potatoes in individual gratin dishes or a shallow casserole dish. Top with onions and Gruyere cheese.
Brown gratin under hot broiler until bubbly, about 2 minutes.