Root Vegetable Gratin

• 4 tablespoons unsalted butter, divided, plus more for baking dish
• 1 1/2 cups coarse fresh breadcrumbs
• 1 1/2 cups grated Parmesan, divided
• 6 sprigs thyme plus 1 tablespoon leaves
• Kosher salt, freshly ground pepper
• 3 cups heavy cream
• 1 cup low-sodium chicken broth
• 1 1/2 pounds celery root, peeled, sliced 1/16" thick
• 1 pound rutabaga, peeled, sliced 1/16" thick
• 1 pound turnips, peeled, sliced 1/16" thick
• 1 pound Yukon Gold potatoes, peeled, sliced 1/16" thick
• 2 garlic cloves, thinly sliced

1. Preheat oven to 400u0b0F. Butter a shallow 2-quart baking dish. Melt 2 tablespoons 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 1/2 cup Parmesan and 1 tablespoon thyme leaves; season with salt and pepper.
2. Bring cream, broth, thyme sprigs, and remaining 2 tablespoons 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; discard thyme. Cover and keep warm.
3. Toss vegetables and garlic in a large bowl; season with salt and pepper. Arrange 1/3 of vegetables in dish and top with 1/2 cup Parmesan. Repeat layers; top with remaining vegetables. Pour cream mixture over; place a piece of parchment paper directly on top of vegetables.
4. Bake until vegetables are crisp-tender and cream is thickened, 50-60 minutes. Uncover, top with breadcrumbs, and bake until gratin is bubbling and breadcrumbs are brown, 15-20 minutes longer. Let sit 10 minutes before serving.

unsalted butter, breadcrumbs, parmesan, thyme, kosher salt, heavy cream, chicken broth, celery root, potatoes, garlic

Taken from www.epicurious.com/recipes/food/views/root-vegetable-gratin-51198860 (may not work)