Two Potato Gratin with Thyme and Shallots

5 from 14 votes

Two Potato Gratin with Thyme and Shallots

Delicious, hearty, and creamy all in one potato gratin. A mandoline is helpful to slice the potatoes quickly and uniformly. This recipe is very easy but so full of flavor.

Prep Time15

Cook Time1

Course: Side Dish

Cuisine: American

Keyword: gratin, holidays, Potatoes, Side dishes

Servings: people

Calories: 288kcal

Author: Sally Humeniuk

Equipment

Mandoline
Large mixing bowl
Small saucepan
2-quart baking dish

Ingredients

2 medium orange skinned sweet potatoes (yams), peeled and sliced into ⅛-inch rounds
2 large russet potatoes, sliced into ⅛-inch rounds- No need to peel
½ cup shallot, sliced
1 ½ tsp kosher salt, or 1 teaspoon table salt
1 ½ cups heavy cream
3 sprigs fresh thyme, plus more thyme leaves for garnish
1 tbsp butter, softened for coating baking dish
2 cups shredded Gruyere cheese, divided or any favorite Swiss cheese
2 cups shredded sharp cheese, divided

Instructions

Preheat oven to 400F°
In a large mixing bowl, toss potato slices and ½ cup shallots with 1 ½ teaspoons of kosher salt. Set aside.
In a small saucepan over medium heat, add 1 ½ cup cream and 3 thyme sprigs. Heat, stirring occasionally, about 5 minutes; set aside to let thyme steep for 15 minutes, then remove sprigs. Pour half of cream mixture into bowl with potatoes and toss with your hands to coat.
Coat a 2-quart baking with 1 Tablespoon of softened butter; layer half of the potato/shallot mixture in the baking dish and top with 1 cup of each of the cheeses. Top with remaining potato/shallots; pour in the remaining cream, plus any cream that accumulated in the bottom of the potato/shallot bowl. Sprinkle with the remaining cheeses.
Cover loosely with foil. Bake for 45 minutes. Uncover and bake 20 to 25 minutes or until the potatoes are tender and cheese is golden brown. If the cheese begins to brown too much, place foil back over the top of the dish until baking is complete (potatoes are tender). Garnish with more fresh thyme leaves to serve.
This dish can sit covered with foil for about 15 minutes before serving if needed while other items in the meal are being completed, or can remain in a 250F° oven for up to 30 minutes before serving. Best served the day of baking for appearance, though leftovers reheat very well up to 2 days after baking.

Notes

You can use whatever cheeses you like in the recipe as long as they are good for melting; choose one that's rather sharp and another with full flavor to provide complex flavors. Do not buy pre-shredded cheese as most are covered with ingredients that prevent clumping but also inhibits ideal melting.
You can switch out the thyme for rosemary with delicious results.
If you prefer more sweet potato than russet in the recipe, use 2 large sweet potatoes and 2 medium russet potatoes and, of course, the recipe is good with just one or the other, but it's a pretty presentation with both.
The amount of cheese in the recipe is plentiful but feel free to add additional cheese to the top after removing the foil for even more of a cheesy top.
Gratins are known for the liquid from the heavy cream so be sure to catch the cream in each portion. The cream and cheese do not combine to be a combined sauce.
Don't skip seeping the thyme in the cream. The flavor is subtle after seeping but wonderful in the dish.

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