- 1/2 teaspoon ground black pepper
- 1 tablespoon unsalted butter
- 1 yellow onion, thinly sliced
- 3 garlic cloves, minced
- 1 1/2 cups heavy cream
- 1/2 cup milk
- 1 1/2 teaspoon kosher salt
- 2 pounds yukon gold or russet potatoes, peeled and sliced into 1/8-inch slices
- 1/2 cup shredded extra sharp Cheddar
- 1 cup shredded gruyere cheese
- 1/4 teaspoon nutmeg
Preheat the oven to 375 degrees F. Butter a large casserole dish. You can use a 9 x 13 or a large oval dish.
In a buttered casserole dish, layer 1/2 of the potatoes, 1/2 the onion, 1/2 the garlic and 1/2 of both cheeses.
Sprinkle with nutmeg, salt and pepper.
Layer the rest of the potatoes, then the onion, garlic and sprinkle both cheeses evenly on top.
I like to use a large plastic measuring cup to mix together cream and milk. Use a 4 cup to make sure you have enough room to mix the cream and milk.
Pour the cream mixture evenly over the top of the potatoes.
Bake uncovered for 50 minutes, until the potatoes are tender and the gratin is bubbly.
Remove from oven and turn on your broiler.
Move rack to a few inches from the broiler. Place casserole dish under broiler and broil for about 5 minutes, until the top turns golden brown.
Let stand for 10 minutes before dishing up. Letting it stand gives everything a chance to cool and firm up, so when you cut into it you get a gorgeous cheesy goodness, and not a runny mess all over your plate. I know it's SO hard to wait, but I promise it's worth it!!