Name: Cheesy Root Vegetable Gratin Recipe
Prep time: 20 min
Cook time: 55 min
Total time: 1 h 15 min
Cuisine: American
Ingredients: 2 pounds (about 900g) mixed root vegetables (potatoes, sweet potatoes, parsnips, carrots), peeled and thinly sliced; 1 small onion, thinly sliced; 2 cloves garlic, minced; 2 tablespoons butter; 2 tablespoons all-purpose flour; 2 cups milk (whole or 2%); 1 1/2 cups shredded sharp cheddar cheese, divided; 1/2 cup grated Parmesan cheese, divided; Salt and black pepper to taste; 1/4 teaspoon ground nutmeg (optional); Fresh thyme leaves (optional)

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Introduction

Cheesy Root Vegetable Gratin is a comforting and flavorful dish that celebrates the natural sweetness of mixed root vegetables. Packed with a creamy cheese sauce and a golden crust, it makes a perfect side for holiday meals or cozy dinners.

The image shows a white bowl filled with shredded orange cheddar cheese and three small white bowls containing white flour, light yellow shredded cheese, and thinly sliced white onions. On a wooden board, there are three piles of thinly sliced vegetables arranged side by side: light yellow potato slices, orange sweet potato slices, and dark red beet slices. Next to the board, there is a white measuring cup with milk and a small glass bowl with pale yellow butter. In the middle is a small glass with light brown mustard. All is set on a white marbled surface. Photo taken with an iphone --ar 4:5 --v 7

Ingredients

2 pounds (about 900g) mixed root vegetables (such as potatoes, sweet potatoes, parsnips, and carrots), peeled and thinly sliced
1 small onion, thinly sliced
2 cloves garlic, minced
2 tablespoons butter
2 tablespoons all-purpose flour
2 cups milk (whole milk or 2%)
1 1/2 cups shredded sharp cheddar cheese
1/2 cup grated Parmesan cheese
Salt and black pepper to taste
1/4 teaspoon ground nutmeg (optional)
Fresh thyme leaves for garnish (optional)

Instructions

Step 1: Preheat your oven to 375°F (190°C). Grease a baking dish (9×13 inches or similar) with butter or cooking spray.
Step 2: Peel and thinly slice the mixed root vegetables. Using a mandoline slicer can help achieve even slices. Place the slices in a large bowl.
Step 3: In a medium saucepan, melt 2 tablespoons of butter over medium heat. Add the sliced onion and minced garlic, sautéing for 3–4 minutes until translucent and fragrant.
Step 4: Sprinkle the flour over the sautéed onions and garlic, stirring constantly for 1–2 minutes to form a roux.
Step 5: Gradually pour in the milk while stirring continuously. Cook until the mixture thickens, about 5–7 minutes.
Step 6: Reduce heat to low. Stir in 1 cup shredded cheddar cheese and 1/4 cup grated Parmesan until melted and smooth. Season with salt, black pepper, and nutmeg if using.
Step 7: Pour the cheese sauce over the sliced vegetables and toss gently to coat evenly.
Step 8: Arrange the coated vegetables in an even layer in the prepared baking dish.
Step 9: Cover the dish with aluminum foil and bake for 35–40 minutes, until the vegetables are tender when pierced.
Step 10: Remove the foil and sprinkle the remaining 1/2 cup cheddar and 1/4 cup Parmesan evenly over the top.
Step 11: Return the gratin to the oven uncovered and bake for an additional 15–20 minutes until the top is golden brown and bubbling.
Step 12: If desired, garnish with fresh thyme leaves. Let cool a few minutes before serving.

Tips & Variations

Use a mandoline slicer to ensure evenly thin vegetable slices for uniform baking.
Try adding a pinch of smoked paprika or cayenne for a subtle spicy kick.
Substitute Gruyère or Fontina cheese for a different but equally delicious flavor.
If you prefer a lighter version, use half-and-half instead of whole milk.

Storage

Store leftovers in an airtight container in the refrigerator for up to 3 days. Reheat in the oven at 350°F (175°C) until warmed through to preserve the crispy topping. Avoid microwaving as it may make the crust soggy.

How to Serve

A large oval cooking dish with golden handles holds a colorful layered potato gratin arranged in five neat rows. The top row has dark orange slices with a slightly crispy texture, followed by a row of pale yellow slices with a creamy, golden cheese layer on top. The middle row features darker, almost purple slices with a glossy, baked finish. Below is a bright orange layer with a slightly charred, crispy edge, and the bottom row returns to pale yellow slices with melted cheese and small herbs sprinkled on top. The dish sits on a white marbled surface next to a beige cloth and an old-fashioned silver spoon. Photo taken with an iphone --ar 4:5 --v 7

Serve this delicious recipe with your favorite sides.

FAQs

Can I prepare this gratin ahead of time?

Yes, you can assemble the gratin and cover it tightly, then refrigerate for up to 24 hours before baking. Add a few extra minutes to the baking time if baking from chilled.

What root vegetables work best in this recipe?

Potatoes, sweet potatoes, parsnips, and carrots work wonderfully together because of their different flavors and textures, but you can also add turnips or rutabagas for variety.