POTATO AND ONION GRATIN
By J. Gagliardi
- 2 pounds yukon gold potatoes (6-7 potatoes), peeled and thinly sliced
- 1 large white sweet onion, peeled and thinly sliced
- 2 cloves garlic, minced
- 1 cup heavy cream
- 1 cup whole milk
- 1/2 cup gruyere or cheddar cheese, grated
- 3 tablespoons unsalted butter
- 3 tablespoons all-purpose flour
- 1 tablespoon fresh rosemary, minced
- 1/2 tablespoon fresh thyme, minced
- 1/4 teaspoon ground nutmeg
- kosher salt and freshly ground pepper, to taste
Preheat oven to 400º F.
Make an overlapping layer of 1/2 of potato slices along the bottom of a 9×13-inch baking dish, then top with 1/2 of onions and garlic.
Season generously salt and pepper, then repeat layers with remaining potatoes, onion and garlic.
Heat butter in a large saucepan over medium heat. Stir in flour and cook, whisking continuously, until smooth and paste-like. About 2 minutes.
Slowly stir in milk and heavy cream and cook for 5-10 minutes, or until thickened, then mix in 1/2 of gruyere and stir until melted and smooth.
Add nutmeg and season with salt and pepper, then taste and adjust seasoning, if necessary.
Pour sauce evenly over potatoes and onions and top with rosemary, thyme and remaining cheese.
Place baking dish in oven and bake for 1 hour, or until potatoes are fork tender and surface is golden brown. (Cover with aluminum foil if cheese is melting and browning too quickly.)
Remove from oven and serve hot.