Root Vegetable Gratin

4 tablespoons unsalted butter, divided, plus more for baking dish

1½ cups coarse fresh breadcrumbs

1½ cups grated Parmesan, divided

2 Tbsp. Thyme

Kosher salt and freshly ground black pepper

2 cups heavy cream

1/2 cup vegetable or chicken broth

1 celery root, peeled, sliced thin

1 rutabaga, peeled, sliced thin

1 turnip, peeled, sliced thin

1-pound Yukon Gold potatoes, sliced thin

2 garlic cloves, thinly sliced

Make sure the root vegetables are cut the same thickness to ensure even cooking

Preheat oven to 400°F.

Butter a shallow 2-qt. baking dish. Melt 2 Tbsp butter in a medium skillet over medium-high heat. Add breadcrumbs; cook, stirring often, until golden brown, 5–7 minutes. Transfer to a small bowl and toss with ½ cup parmesan and 1 Tbsp thyme leaves; season with salt and pepper and set aside.

Bring cream, broth, 1 Tbsp thyme, and remaining 2 Tbsp butter to a simmer in a medium saucepan over medium heat; season with salt and pepper. Remove from heat, cover, and let sit 10 minutes. Cover; keep warm.

Toss vegetables in a large bowl; season with salt and pepper. Arrange ⅓ of vegetables in dish and top with ½ cup parmesan. Repeat layers; top with remaining vegetables. Pour cream mixture over; place a piece of parchment paper directly on top of gratin.

Bake until vegetables are crisp-tender and cream is thickened, check at 45 minutes to see if fork tender. If ready then uncover, top with breadcrumb mixture, and bake until gratin is bubbling and breadcrumbs are brown, 15–20 minutes longer. Let sit 10 minutes before serving.