Spiralized Winter Veggie Gratin is the perfect holiday gluten-free side dish! Made with spiralized vegetable gratin is made with sweet potatoes, butternut squash, carrots, and parsnips and topped with a white sauce and Gruyere cheese.
Preheat oven to 400 degrees F. Spray a 9” x 13” casserole dish with olive oil.
In a large bowl, combine sweet potato, carrots, squash and parsnips.
Add the olive oil, 1 tablespoon thyme, oregano, 2 tablespoons parsley, 1 teaspoon salt and pepper. Toss well to coat.
Transfer to prepared dish and roast for 40 to 50 minutes, until the vegetables are very tender, tossing halfway through.
Meanwhile, prepare sauce.
Heat a medium non-stick pan over medium heat. Add butter and let it melt, add the shallots and cook until softened, about 4 to 5 minutes.
Sprinkle the flour over the shallots to make a roux, whisking for 1 to 2 minutes. Add the milk and stir with a wooden spoon until the roux is incorporated into the milk.
Cook over medium-low heat for about 4 minutes, stirring, until the sauce thickens.
Add fresh thyme, parmesan and half of the grated Gruyere cheese into the white sauce and stir until the cheese is melted and incorporated into the sauce.
Pour over the veggies and top with the remaining cheese. Bake 10 minutes. Top with remaining parsley and serve.