½cupbread crumbs (optional)panko for sprinkling on top
2tablespoonsparsley or chives (optional)minced
INSTRUCTIONS
Preheat the oven to 350°F.
Peel and slice the potatoes. Place the potatoes in a large bowl filled with cold water to cover them. This will keep them from turning brown.
3 pounds potatoes
Add the butter to a large saucepan. Add the shallot and cook on medium-low heat until they begin to caramelize.
3 tablespoons butter, 1 small shallot
Add the garlic and sauté for a few minutes until the garlic is fragrant.
1 clove garlic
Sprinkle the onion mixture with the flour and cook over medium-high heat until the flour bubbles and thickens slightly. You don't want the flour to brown. top.
3 tablespoons flour
Add the heavy cream. You want to add in a small amount at first and whisk until smooth. Continue to add the cream a small amount at a time, whisking thoroughly between each addition to ensure that the béchamel sauce stays smooth and creamy.
2 cups heavy cream
Add the grated parmesan cheese to the cream mixture. Remove the white sauce from the stovetop and whisk to incorporate the parmesan.
1 cup parmesan cheese
Strain the water off of the potatoes. Add half of the potato slices to a casserole dish—layer with half of the cheese sauce and spread with a spatula. Add half of the shredded cheese. Repeat for the second layer.
7 ounces cheddar, 6 ounces Gruyere cheese, ½ cup bread crumbs (optional)
Bake. Cover the casserole dish with aluminum foil and bake for one hour. Uncover and bake for another 2o to 30 minutes until the potatoes are golden brown on top.
2 tablespoons parsley or chives (optional)
RECIPE TIPS
Type of potatoes. Use Yukon gold or russet potatoes. Yukon gold potatoes will have a slightly longer cook time.
Cornstarch slurry. To make this recipe without flour, use a cornstarch slurry. The typical ratio for a cornstarch slurry in a sauce is 1 part cornstarch to 2 parts water. Use 1 tablespoon of cornstarch for every cup of liquid that you're thickening. **For this recipe use 2 tablespoons of cornstarch+ 4 tablespoons of water.