Spiralized Winter Veggie Gratin is a delightful gluten-free side that shines on any holiday table. Thin ribbons of sweet potato, butternut squash, carrots and parsnips are tossed with olive oil and fresh herbs, roasted until tender, then finished with a creamy white sauce and melted Gruyère for a rich, comforting dish.
Spiralized Winter Veggie Gratin
Using a spiralizer speeds up the prep and creates delicate ribbons that roast evenly. The mix of sweet potatoes, parsnips, carrots and butternut squash brings both sweetness and earthy depth; the white sauce (a simple béchamel-style mix) binds the vegetables and the Gruyère browns to create a golden, cheesy crust. This gratin is naturally festive, gluten-free when you choose a gluten-free flour, and pairs beautifully with roasted poultry, mashed potatoes, or a simple green salad.
Make-ahead and storage
This gratin is especially convenient because it can be assembled up to two days in advance. Spiralize the vegetables, roast them, and prepare the white sauce ahead of time. Combine the vegetables and sauce in the baking dish, top with cheese, and loosely cover with foil so it doesn’t touch the surface. Refrigerate until ready to bake. When you plan to serve, remove the dish from the fridge about an hour before baking to take the chill off, keep the foil on, and bake until warmed through and the cheese is melted—about 30 minutes at 350°F (175°C).
Tips for spiralizing firm winter vegetables
- Choose a sturdy spiralizer built to handle denser vegetables like butternut squash and sweet potatoes. A manual, heavy-duty unit with strong grips works best.
- Smaller vegetables such as carrots and turnips should be at least 1½ inches (about 4 cm) in diameter for consistent spiralizing and to avoid breaking.
- Prep ahead: spiralized vegetables keep well in zip-top bags in the refrigerator for several days. This makes day-of assembly quick and easy.
If you enjoy using a spiralizer beyond zucchini noodles, this gratin is a great reminder that many firm vegetables transform beautifully into ribbons. Spiralized veggies add visual interest, reduce cooking time compared with thick slices, and create a pleasing texture in layered dishes.
Recipe
Spiralized Winter Veggie Gratin — Details
Yield: 8 servings (about 1/2 cup per serving)
Prep time: 10 mins · Cook time: 1 hr · Total: 1 hr 10 mins
Ingredients
- Olive oil spray (for greasing the dish)
- 1 medium (about 7 oz) sweet potato, peeled and spiralized
- 1 lb carrots, peeled and spiralized (about 1.5″ diameter recommended)
- 1½ lb whole butternut squash, peeled and spiralized
- 2 medium parsnips (about 7 oz total), peeled and spiralized
- 1½ tablespoons olive oil
- 4 teaspoons fresh chopped thyme, divided
- 1 tablespoon fresh chopped oregano
- 3 tablespoons fresh chopped Italian parsley, divided
- 1¼ teaspoons Kosher salt
- Freshly ground black pepper, to taste
- ½ tablespoon butter
- 1/3 cup chopped shallots
- 3 teaspoons all-purpose flour (use gluten-free flour to keep it GF)
- 1 cup fat-free milk
- 1 tablespoon grated Parmesan cheese
- 2½ ounces grated Gruyère cheese, divided
Instructions
- Preheat the oven to 400°F (200°C). Spray a 9″ x 13″ casserole dish with olive oil.
- In a large bowl, combine the spiralized sweet potato, carrots, butternut squash and parsnips.
- Add the olive oil, 1 tablespoon of the thyme, oregano, 2 tablespoons of the parsley, 1 teaspoon salt and freshly ground black pepper. Toss thoroughly to coat the vegetables evenly.
- Transfer the seasoned vegetables to the prepared baking dish and roast for 40–50 minutes, tossing once halfway through, until the vegetables are very tender and beginning to caramelize.
- While the vegetables roast, make the white sauce: heat a medium nonstick pan over medium heat. Add the butter; when melted, add the shallots and sauté until softened, about 4–5 minutes.
- Sprinkle the flour over the shallots and whisk for 1–2 minutes to form a roux. Gradually add the milk, stirring until the roux is fully incorporated into the milk and smooth.
- Reduce heat to medium-low and cook, stirring, for about 4 minutes until the sauce thickens to a creamy consistency.
- Stir in the remaining fresh thyme, the Parmesan, and half of the grated Gruyère until the cheeses melt into the sauce.
- Pour the cheese sauce over the roasted vegetables, sprinkle the remaining Gruyère on top, and bake for about 10 minutes more until the cheese melts and the top is lightly golden.
- Garnish with the remaining chopped parsley, let rest a few minutes, then serve warm.
Notes and variations
To keep this dish gluten-free, substitute a gluten-free all-purpose flour in the white sauce. For a richer sauce, use whole milk or a mix of milk and light cream. If Gruyère is unavailable, a good melting Swiss cheese can be a substitute, though Gruyère offers a distinctive nutty flavor. Leftovers keep covered in the refrigerator for 3–4 days and can be reheated in a 350°F oven until warmed through.
Nutrition (per 1/2 cup)
Calories: 176 · Carbohydrates: 25 g · Protein: 6 g · Fat: 6.5 g · Fiber: 5 g · Sugar: 8 g · Sodium: 277 mg