Cheesy Root Vegetable Gratin

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Golden, sliceable layers for your holiday table (about 75–90 minutes)

Thin-sliced roots baked in silky garlic cream with a toasty Parmesan cap—crowd-pleasing comfort that carves cleanly.

Cheesy Root Vegetable Gratin—layered potatoes, parsnip, sweet potato with Parmesan crumb and sun-dried tomatoes; Thanksgiving side.

Why You’ll Love It

  • Root Vegetable Gratin payoff: Layers of sweet potato, Yukon gold, parsnip, rutabaga & carrot = sweet-savory depth. (Root Vegetable Gratin)
  • Thanksgiving food sides win: Scales to a 9×13 and holds heat beautifully. (Thanksgiving Food Sides / Thanksgiving Side Dishes)
  • Make-ahead friendly: Par-bake, chill, and finish day-of. (Thanksgiving Recipes Side Dishes)
  • Vegetarian main or side: Big flavor, no meat—perfect Receitas Vegetarianas boards.
  • Tomatoes option: Sun-dried tomato–Parmesan crumb adds umami pop and color. (Tomatoes)
  • Veggie dishes everyone eats: Familiar flavors, creamy texture, irresistible cheese. (Vegetable Side Dishes / Veggie Dishes / Vegetable Dishes)

Ingredients (notes only)

Roots (3 lb / 1.4 kg total, 1/8-in slices)

  • Yukon golds (creamy body) • Sweet potato (caramel notes) • Parsnip & rutabaga (earthy) • Carrot (color & sweetness)

Aromatics & Sauce

  • Butter + olive oil (flavor + browning)
  • Shallot & garlic (softened, not browned)
  • Flour for light roux (or cornstarch slurry for GF)
  • Heavy cream + whole milk (3 cups total), thyme, bay, pinch nutmeg, salt/pepper

Cheese

  • Gruyère (melty, nutty), Parmesan (salty finish)

Crisp Topping

  • Panko, Parmesan, olive oil, chopped sun-dried tomatoes (optional), chopped parsley

Step-by-Step

  1. Heat oven to 375°F/190°C. Grease a 9×13-in (3-qt) dish. Mandoline roots to 1/8 in / 3 mm; keep in cold water, then pat very dry.
  2. Make sauce (7–8 min): Sauté 1 minced shallot in 2 Tbsp butter + 1 Tbsp oil until soft. Stir in 3 Tbsp flour 1 min. Gradually whisk in 2 cups cream + 1 cup milk, 2 tsp thyme, 1 bay leaf, 2 minced garlic, 1¼ tsp salt, ½ tsp pepper, pinch nutmeg. Simmer gently to light nappe; remove bay.
  3. Layer: Shingle half the roots; season lightly. Ladle half the sauce and scatter 1 cup shredded Gruyère. Repeat with remaining roots, sauce, and 1 cup Gruyère.
  4. Cover & bake: Tightly foil. Bake 45–50 min until almost tender.
  5. Top & brown: Mix ¾ cup panko + ½ cup finely grated Parmesan + 2 Tbsp olive oil + 2 Tbsp chopped sun-dried tomatoes (optional). Uncover gratin, sprinkle topping; bake 20–25 min until deeply golden and a knife slides through easily (center ~205°F/96°C).
  6. Rest 15 min for clean slices. Garnish with parsley.

Pro Tips

  • Even slices = even doneness. Mandoline or food processor slicing disc.
  • Season in layers. A tiny pinch of salt/pepper over each root layer brightens flavor.
  • Steam first, brown later. Foil traps moisture, then uncover for crust.
  • Grate cheese fine. Helps it melt through the stacks instead of clumping.

Variations (mapped to interests)

  • Sun-Dried Tomato Parm Crumb: Boost umami + color. (Tomatoes)
  • Herb & Shallot Light: Use 2½ cups milk + ½ cup cream; extra thyme/parsley. (Healthyish Vegetable Dishes)
  • Gluten-Free: Replace flour with 2½ Tbsp cornstarch whisked into cold milk; simmer to thicken.
  • Receitas Vegetarianas: Verify vegetarian-rennet cheeses; swap butter for olive oil. (Receitas Vegetarianas)
  • Broccoli-Root Sheet Pan: Par-roast small broccoli florets 10 min; tuck on top for last 15 min.

How to Serve

Perfect beside roast turkey, chicken, beef, or glazed ham. For a lighter plate, add a simple arugula salad or a lemony quinoa pilaf.

Make Ahead & Storage

  • Par-bake: Cover and bake 45–50 min; cool, cover, and refrigerate up to 48 h. Finish uncovered 25–30 min until bubbling and browned.
  • Fridge: 4 days, covered.
  • Reheat: 325°F/165°C covered 20–25 min; loosen with splash of warm milk if thick.
  • Freeze: Not ideal; dairy can separate.

FAQs

Can I use only one or two vegetables? Yes—Yukon + sweet potato is great; keep total weight the same.
Why is my sauce thin? Simmer the roux-dairy mix a minute longer, or rest the baked gratin 15 minutes.
Do I need cheese? No—the gratin is rich without it; add more Parm on top only if desired.
Can I add tomatoes? Yes—use chopped sun-dried tomatoes in the crumb or layer in thin roasted tomato slices near the top.

Simple Nutrition (estimate per 12 servings)

≈290 kcal • 9 g protein • 27 g carbs • 17 g fat • 420 mg sodium
Estimates only; vary by cheeses and vegetables.

Sarah

Cheesy Root Vegetable Gratin

Sliceable layers of mixed root vegetables baked in a garlic-thyme cream with Gruyère and a Parmesan crumb topping. Perfect for holidays or cozy dinners.
Print Recipe Pin Recipe
Prep Time 25 minutes
Cook Time 1 hour 15 minutes
Total Time 1 hour 45 minutes
Servings: 12 servings
Course: Side Dish
Cuisine: American–French comfort
Calories: 290
Ingredients Equipment Method Nutrition Notes

Ingredients

  • 3 lb (1.4 kg) mixed root vegetables, sliced 1/8 inch thick (Yukon gold, sweet potato, parsnip, rutabaga, carrot)
  • 2 Tbsp unsalted butter
  • 1 Tbsp olive oil
  • 1 small shallot, minced
  • 3 Tbsp all-purpose flour (or 2½ Tbsp cornstarch + 3 Tbsp water for gluten-free)
  • 2 cups heavy cream
  • 1 cup whole milk
  • 2 tsp fresh thyme leaves (or 1 tsp dried)
  • 1 pinch nutmeg
  • 2 cloves garlic, minced
  • 1 1/4 tsp kosher salt
  • 1/2 tsp black pepper
  • 2 cups (8 oz / 225 g) shredded Gruyère cheese, divided
  • 3/4 cup panko breadcrumbs
  • 1/2 cup finely grated Parmesan cheese
  • 2 Tbsp olive oil (for topping)
  • 2 Tbsp chopped sun-dried tomatoes (optional)
  • 1 Tbsp chopped parsley (for topping)

Equipment

  • mandoline slicer for even root slices
  • 9×13-inch baking dish
  • saucepan for cream sauce
  • whisk
  • foil for covering dish
  • oven
  • mixing bowl for crumb topping

Method

  • Preheat oven to 375°F (190°C). Grease a 9×13-inch baking dish.
  • In a saucepan, heat butter and olive oil over medium heat. Add shallot and sauté 3–4 minutes. Stir in flour and cook 1 minute.
  • Whisk in cream and milk gradually. Add thyme, bay leaf, garlic, nutmeg, salt, and pepper. Simmer 3–5 minutes until lightly thickened. Remove bay leaf.
  • Layer half the sliced roots in the dish, seasoning lightly. Pour half the sauce and sprinkle 1 cup Gruyère. Repeat with remaining roots, sauce, and 1 cup Gruyère.
  • Cover tightly with foil and bake 45–50 minutes.
  • In a bowl, mix panko, Parmesan, olive oil, sun-dried tomatoes (if using), and parsley. Uncover gratin, top evenly with crumb mix, and bake 20–25 minutes until golden and tender (center ~205°F/96°C).
  • Rest 15 minutes before slicing. Garnish with parsley and serve warm.

Nutrition

Calories: 290kcalCarbohydrates: 27gProtein: 9gFat: 17gSaturated Fat: 10gPolyunsaturated Fat: 1gMonounsaturated Fat: 5gCholesterol: 50mgSodium: 420mgPotassium: 680mgFiber: 4gSugar: 7gVitamin A: 9500IUVitamin C: 14mgCalcium: 190mgIron: 2mg

Notes

Vegetarian: Use cheeses made with vegetarian rennet.
Gluten-free: Replace flour with 2½ Tbsp cornstarch mixed with 3 Tbsp water.
Lighter version: Swap 1 cup cream for milk and add extra thyme.
Equipment: Mandoline, 9×13-inch baking dish, foil.
Alternate Methods: Mini gratins (ramekins): Bake at 375°F (190°C) 30–35 min covered, then 10–12 min uncovered to brown.
Convection oven: 350°F (175°C); start checking 10 minutes earlier for doneness.
Tried this recipe?Mention @WPRecipeMaker or tag #wprecipemaker!

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