Layered potatoes, onions, Gruyère, and cheddar baked under a golden crust. Comforting vegetarian main dish.
# What you'll need:
→ Vegetables
01 - 2.6 lbs floury potatoes (Maris Piper or Yukon Gold), peeled and thinly sliced
02 - 2 medium onions, thinly sliced
03 - 2 cloves garlic, minced
→ Dairy
04 - 5 oz Gruyère cheese, grated
05 - 5 oz mature cheddar cheese, grated
06 - 1 1/4 cups heavy cream
07 - 3.5 tablespoons unsalted butter
08 - 1/2 cup whole milk
→ Seasonings
09 - 1/2 teaspoon freshly grated nutmeg
10 - 1 teaspoon Dijon mustard
11 - Salt and freshly ground black pepper to taste
→ Topping
12 - 2 tablespoons fresh chives, finely chopped (optional)
# Method:
01 - Preheat oven to 375°F. Butter an 8-cup ovenproof pie or casserole dish.
02 - Melt butter in a large saucepan over medium heat. Add onions and garlic, cooking for 6 to 8 minutes until softened and translucent but not browned. Remove from heat.
03 - In a bowl, whisk together heavy cream, milk, Dijon mustard, nutmeg, salt, and black pepper.
04 - Arrange half the potato slices in the prepared dish with slight overlap. Top with half the onion mixture and sprinkle with half the Gruyère and cheddar cheeses.
05 - Repeat with remaining potato slices, onion mixture, and cheeses to create a second complete layer.
06 - Pour the cream mixture evenly over all layers. Use a spatula to press down gently and compact the layers.
07 - Cover the dish with aluminum foil and bake for 40 minutes.
08 - Remove the foil and bake for an additional 20 minutes until the top is golden and the filling is bubbling at the edges.
09 - Allow the pie to rest for 10 minutes before serving. Garnish with fresh chives if desired.