Go Back

Cheesy Root Vegetable Gratin

Cheesy root vegetable gratin with thin Yukon gold, sweet potato, and parsnip slices baked until bubbling and golden under a Gruyere-Parmesan crust. Warm cream and aromatics soak the layers for a creamy, fork-tender finish.
Print Recipe Pin Recipe
Prep Time 25 minutes
Cook Time 1 hour 10 minutes
resting 10 minutes
Total Time 1 hour 45 minutes
Servings: 8 servings
Course: Side Dish
Cuisine: French-inspired
Calories: 460
Ingredients Equipment Method Notes

Ingredients
  

Yukon gold potatoes
  • 1 lb Yukon gold potatoes, peeled and thinly sliced
sweet potatoes
  • 1 lb sweet potatoes, peeled and thinly sliced
parsnips
  • 2 parsnips, peeled and thinly sliced
heavy cream
  • 1.5 cup heavy cream
whole milk
  • 0.5 cup whole milk
garlic
  • 3 garlic, minced
fresh thyme leaves
  • 1 tsp fresh thyme leaves
salt
  • 1.5 tsp salt
black pepper
  • 0.5 tsp black pepper
nutmeg
  • 0.25 tsp nutmeg
Gruyere
  • 2 cup shredded Gruyere, divided
Parmesan
  • 0.5 cup grated Parmesan

Equipment

  • 1 sheet pan

Method
 

Prep and heat
  1. Preheat the oven to 375F and butter a 9x13-inch baking dish.
  2. Warm the heavy cream, whole milk, minced garlic, thyme leaves, salt, black pepper, and nutmeg until steaming, then remove from the heat.
Layer and bake
  1. Layer a third of the Yukon gold potatoes, sweet potatoes, and parsnips in the baking dish, then top with a third of the shredded Gruyere.
  2. Repeat the layers twice so the vegetables are used up, then pour the warm cream mixture evenly over the top.
  3. Cover with foil and bake for 45 minutes.
  4. Uncover, sprinkle with grated Parmesan, and bake 20-25 minutes until bubbly, golden, and fork-tender.
Rest and serve
  1. Rest the gratin for 10 minutes before serving so the layers set.

Notes

Pro tip: slice the vegetables very thin and evenly so they cook through at the same rate; if your slices vary in thickness, spread the thinner slices toward the center. Store covered in the refrigerator for up to 4 days; reheat individual portions in the oven or microwave until hot. Freeze is not recommended because the creamy dairy can separate after thawing. For a lighter swap, use half-and-half instead of the heavy cream to reduce richness while keeping the creamy texture.