1. 3/4 teaspoon salt
2. 1/2 teaspoon ground black pepper
3. 1/2 teaspoon thyme
4. 2 tablespoons butter, divided
5. 1 thinly sliced sweet onion
6. 1 1/2 pounds Yukon gold potatoes, peeled and thinly sliced
7. 1 cup shredded Gruyere cheese
Prep:20 Minutes, Cook:43 Minutes, Ready In:1 Hours 8 Minutes
1. integrate salt, pepper, and thyme in a bowl.
2. soften 1 tablespoon butter in a 10-inch skillet over medium warmness. cook and stir onions till soft and golden brown, approximately eight minutes. flow to a bowl.
3. soften last 1 tablespoon butter in the skillet; put off from heat.
4. set up 1/3 of potato slices within the skillet in a barely overlapping layer. sprinkle with 1/2 teaspoon of the salt mixture. top with half of of the onions and half of of the gruyere cheese. repeat layers, ending with potatoes; sprinkle with final salt mixture.
5. cowl and cook dinner over medium-low warmth, reducing warmth to low if important, till potatoes are gentle, approximately 30 minutes. uncover and keep cooking, approximately 5 mins. run a spatula around edges to loosen; allow cool, 5 to ten minutes.
6. invert potatoes carefully onto a serving dish.