Pommes Anna with Gruyere

Combine salt pepper and thyme in a bowl.

Melt 1 tablespoon butter in a 10-inch skillet over medium heat. Cook and stir onions until soft and golden brown about 8 minutes. Move to a bowl.

Melt remaining 1 tablespoon butter in the skillet; remove from heat.

Arrange 1/3 of potato slices in the skillet in a slightly overlapping layer. Sprinkle with 1/2 teaspoon of the salt mixture. Top with 1/2 of the onions and 1/2 of the Gruyere cheese. Repeat layers ending with potatoes; sprinkle with remaining salt mixture.

Cover and cook over medium-low heat reducing heat to low if necessary until potatoes are tender about 30 minutes. Uncover and continue cooking about 5 minutes. Run a spatula around edges to loosen; let cool 5 to 10 minutes.

Invert potatoes carefully onto a serving dish.