Scalloped Yukon Gold and Sweet Potato Gratin

Ingredients

• •1 1/2 pound medium Yukon Gold potatoes
• •1 1/2 pound medium red-skinned sweet potatoes
• •2 cup heavy whipping cream
• •1/4 cup butter
• •2 garlic cloves, minced
• •1 tbsp fresh parsley, minced
• •1 tbsp fresh rosemary, minced
• •1 tbsp fresh sage, minced
• •1 tbsp fresh thyme, minced
• •1 1/2 tsp salt
• •3/4 tsp pepper
• •5 ounce Gruyere, coarsely grated

Steps

1. 1Fill large bowl with cold water. Working with 1 potato at a time, peel, then cut into 1/8-inch-thick rounds and place in bowl with water.
2. 2Combine cream, butter, and garlic in medium saucepan; bring to simmer. Remove from heat.
3. 3Mix all herbs, salt, and pepper in small bowl.
4. 4Butter 13×9×2-inch glass baking dish. Drain potatoes, then pat dry with kitchen towels. Transfer half of potatoes to prepared baking dish. Use hands to distribute and spread evenly. Sprinkle with half of herb mixture, then half of cheese. Repeat with remaining supplies. Pour cream mixture over gratin, pressing lightly to submerge potato mixture as much as possible. (All of this can be done up to 6 hours ahead: cover with plastic wrap and chill. Remove plastic wrap before baking.)
5. 5Preheat oven to 400°F. Cover gratin tightly with foil. Bake 30 minutes. Uncover, and bake until top of gratin is golden and most of liquid is absorbed, about 25 minutes longer. Let stand 10 minutes; serve.