📝 Instructions
= Recipe
1. Heat oven to 350 degrees and butter a 2-quart gratin dish with more unsalted butter.
2. Wash the 2 large, trimmed and halved lengthwise leeks to remove any grit and slice thinly crosswise.
3. Using a mandoline or sharp knife, slice the 1 1/2 pounds peeled Yukon Gold potatoes into rounds, 1/8-inch thick. Toss with 0.75 tsp kosher salt and 0.25 tsp ground black pepper. Layer the rounds in the gratin dish.
4. Melt the 2 tbsp unsalted butter in a large skillet over medium heat. Add leeks, remaining kosher salt and ground black pepper, and 2 thyme sprigs. Cook, stirring, until leeks are tender and golden, 5 to 7 minutes.
5. Discard thyme and scatter the leeks over the potatoes.
6. Add 1 cup heavy cream, 1 fat clove, finely chopped garlic and 1 bay leaf to the skillet, scraping up browned bits of leeks from the bottom of the pan. Simmer gently for 5 minutes.
7. Stir in 0.25 tsp freshly ground nutmeg.
8. Pour the cream over the leeks and potatoes and top with the 0.75 cup, grated Gruyère.
9. Cover with aluminum foil and transfer to the oven. Bake for 40 minutes, uncover and bake until the cheese is bubbling and golden, 15 to 20 minutes longer.
10. Let cool slightly before serving.
