Lyonnaise Potatoes

• portions: 4 servings
• temps total: 40 minutes

Ingrédients

2 lb. Yukon Gold potatoes (about 6 small), peeled, sliced into ¼"-thick rounds

3 Tbsp. plus 1¼ tsp. Diamond Crystal or 2 Tbsp. Morton kosher salt, divided; plus more

4 Tbsp. distilled white vinegar, divided

5 Tbsp. unsalted butter, divided

2 medium onions, thinly sliced

2 garlic cloves, finely grated

2 Tbsp. extra-virgin olive oil

3 Tbsp. finely chopped parsley, divided

½ tsp. freshly ground pepper, plus more

Instructions

Line a large rimmed baking sheet with a layer of paper towels or a kitchen towel. Bring 2 lb. Yukon Gold potatoes (about 6 small), peeled, sliced into ¼"-thick rounds, 3 Tbsp. Diamond Crystal or 1 Tbsp. plus 2¼ tsp. Morton kosher salt, 3 Tbsp. distilled white vinegar, and 8 cups cold water to a boil in a medium Dutch oven or other heavy pot. Immediately reduce heat to medium and simmer until potatoes are fork-tender, 7–9 minutes. Drain, transfer to prepared baking sheet, and pat dry.

Meanwhile, heat 2 Tbsp. unsalted butter in a large high-sided skillet over medium-high until sizzling. Add 2 medium onions, thinly sliced, and ½ tsp. Diamond Crystal or ¼ tsp. Morton kosher salt and cook, stirring often to prevent burning and adding 2 garlic cloves, finely grated, 1 minute before onions are finished, until softened, golden brown all over, and dark and frizzled in spots, 8–12 minutes. Using a slotted spoon, transfer to a plate and wipe out pan (wash if very burnt or browned).

Heat 2 Tbsp. extra-virgin olive oil and remaining 3 Tbsp. unsalted butter in pan over medium-high until butter is melted. Add half of the potatoes and cook, undistributed, until browned underneath, about 4 minutes. Turn over and cook until other side is browned, about 4 minutes. Using slotted spoon, transfer potatoes to plate with onions. Repeat with remaining potatoes in oil left in pan; do not transfer to plate. (It’s okay if the butter starts to brown.)

Return potatoes and onions on plate to pan and add 2 Tbsp. finely chopped parsley, ½ tsp. freshly ground pepper, and remaining 1 Tbsp. distilled white vinegar, and ¾ tsp. Diamond Crystal or ½ tsp. Morton kosher salt. Cook, tossing, just until heated through, about 2 minutes. Remove from heat and top with remaining 1 Tbsp. finely chopped parsley. Taste potatoes and season with more salt and pepper if needed.