Introduction

This Cheesy Herb Butternut Squash Gratin is a comforting and elegant side dish perfect for fall and winter meals. Tender slices of butternut squash are baked in a rich, creamy cheese sauce infused with fresh herbs, then topped with a crunchy, golden panko crust. It’s an easy way to elevate a simple vegetable into something truly special.

This image shows a white oval baking dish filled with a baked pasta dish. The top layer is golden brown and crispy, covered with breadcrumbs and sprinkled with green herbs. Below the crunchy top, you see a creamy, cheesy sauce with a light yellow color that coats ridged pasta tubes closely stacked inside. The edges of the pasta show a slightly darker baked color, giving a textured look. The dish sits on a white marbled surface, with a white and gray striped cloth and a shiny silver spoon placed near the dish on the left side, while stacks of white plates are on the right. Photo taken with an iphone --ar 4:5 --v 7

Ingredients

2 tablespoons olive oil
1 small onion, finely chopped
2 cloves garlic, minced
2 teaspoons fresh thyme leaves
1 teaspoon fresh rosemary, finely chopped
¼ teaspoon salt
½ teaspoon black pepper
2 tablespoons Kikkoman® Umami Joy Sauce®
1 cup heavy cream
1 cup whole milk
1 cup sharp cheddar cheese, freshly grated
1 cup Gruyère cheese, freshly grated
1 large butternut squash, peeled and thinly sliced (about ¼” thick)
½ cup Kikkoman® Panko Bread Crumbs
1 tablespoon melted butter
2 tablespoons Parmesan cheese, grated
½ teaspoon garlic powder
Optional: 1 tablespoon fresh parsley, chopped, for garnish

Instructions

Step 1: Preheat your oven to 375°F and lightly grease a 2-quart baking dish to prevent sticking.
Step 2: Heat olive oil in a skillet over medium heat. Add the chopped onion and cook until translucent, about 5 minutes. Stir in garlic, thyme, rosemary, salt, and pepper, cooking until fragrant.
Step 3: Pour in the Umami Joy Sauce, cream, and milk. Bring the mixture to a simmer, then reduce heat. Stir in cheddar and Gruyère cheeses until melted and smooth. Remove from heat.
Step 4: Arrange the thinly sliced butternut squash in the prepared baking dish, slightly overlapping the slices. Pour the cheese sauce evenly over the squash.
Step 5: In a small bowl, mix together panko bread crumbs, melted butter, Parmesan cheese, and garlic powder until evenly coated. Sprinkle this mixture evenly over the gratin.
Step 6: Cover the baking dish loosely with foil and bake for 20 minutes. Then remove the foil and bake for an additional 10-15 minutes until the topping is golden brown and crispy.
Step 7: Let the gratin rest for 5 minutes before serving. Garnish with chopped fresh parsley if desired.

Tips & Variations

Use a mandoline slicer to achieve thin, even slices of butternut squash for even cooking.
Substitute Gruyère with fontina or mozzarella for a milder cheese flavor.
For a dairy-free option, try coconut cream and a plant-based cheese alternative.
Add a pinch of nutmeg to the cheese sauce for a warm, subtle spice.
Sprinkle extra fresh herbs like sage or chives on top for added freshness.

Storage

Store any leftovers in an airtight container in the refrigerator for up to 3 days. Reheat gently in the oven at 350°F until warmed through to maintain the crispy topping. Avoid microwaving to keep the panko crust crunchy.

How to Serve

The image shows a white oval baking dish filled with a baked macaroni and cheese dish. The top layer is golden brown with a crunchy breadcrumb topping scattered with small green herbs. Beneath the crunchy top, creamy cheese sauce bubbles around tender macaroni pasta ridged and curled, visible in shades of yellow and light orange. The edges of the dish show the sauce caramelized and slightly browned. The dish sits on a white marbled surface with a gray and white striped cloth underneath, next to a silver spoon and stacked white plates. photo taken with an iphone --ar 4:5 --v 7

Serve this delicious recipe with your favorite sides.

FAQs

Can I prepare the gratin ahead of time?

Yes, you can assemble the gratin up to a day before baking. Cover it tightly and keep it refrigerated. Bake as directed, adding a few extra minutes if needed.

What can I use if I don’t have Kikkoman® Umami Joy Sauce®?

If you don’t have Umami Joy Sauce, a splash of soy sauce or Worcestershire sauce can add a similar depth of flavor to the cheese sauce.

Cheesy Herb Butternut Squash Gratin with Panko Topping Recipe

Print Recipe

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4.5 from 131 reviews

This Cheesy Herb Butternut Squash Gratin with Panko Topping is a creamy, comforting casserole featuring thinly sliced butternut squash baked in a rich cheese sauce made with sharp cheddar and Gruyère, infused with fresh thyme and rosemary. A crisp, buttery panko topping adds a perfect golden crunch, making it an elegant side dish perfect for autumn and winter dinners.

Author: Dana
Prep Time: 20 minutes
Cook Time: 35 minutes
Total Time: 55 minutes
Yield: 6 servings 1x
Category: Side Dish
Method: Baking
Cuisine: American

Ingredients

Scale

For Gratin

2 tablespoons olive oil
1 small onion, finely chopped
2 cloves garlic, minced
2 teaspoons fresh thyme leaves
1 teaspoon fresh rosemary, finely chopped
¼ teaspoon salt
½ teaspoon black pepper
2 tablespoons Kikkoman® Umami Joy Sauce®
1 cup heavy cream
1 cup whole milk
1 cup sharp cheddar cheese, freshly grated
1 cup Gruyère cheese, freshly grated
1 large butternut squash, peeled and thinly sliced (about ¼” thick)

For Panko Topping

½ cup Kikkoman® Panko Bread Crumbs
1 tablespoon melted butter
2 tablespoons Parmesan cheese, grated
½ teaspoon garlic powder
Optional: 1 tablespoon fresh parsley, chopped, for garnish

Instructions

Preheat and Prepare Baking Dish. Preheat your oven to 375°F (190°C) and lightly grease a 2-quart baking dish to prevent sticking and ensure easy clean-up.
Sauté Aromatics. Heat olive oil in a skillet over medium heat. Once hot, add the finely chopped onion and cook until translucent, about 5 minutes. Stir in the minced garlic, fresh thyme, rosemary, salt, and black pepper. Cook until fragrant, about 1 minute.
Add Umami Sauce and Dairy. Pour in the Kikkoman® Umami Joy Sauce®, then add the heavy cream and whole milk. Bring this mixture to a gentle simmer, then reduce the heat to low to avoid boiling.
Melt Cheeses into Sauce. Stir in the freshly grated sharp cheddar and Gruyère cheeses until fully melted and the sauce is smooth. Remove the skillet from heat to prevent the sauce from curdling.
Arrange Squash in Baking Dish. Lay the thinly sliced butternut squash in the prepared baking dish, slightly overlapping each slice for even coverage.
Pour Cheese Sauce Over Squash. Evenly pour the hot cheese sauce over the arranged butternut squash to coat thoroughly.
Prepare and Add Panko Topping. In a small bowl, combine the panko bread crumbs, melted butter, grated Parmesan cheese, and garlic powder. Mix until the panko is evenly coated. Sprinkle this mixture evenly over the top of the gratin.
Bake Covered and Uncovered. Cover the baking dish loosely with foil and bake in the preheated oven for 20 minutes. Then, remove the foil and bake uncovered for an additional 10-15 minutes until the panko topping is golden brown and crispy.
Rest and Garnish. Allow the gratin to rest for 5 minutes before serving to set. Garnish with freshly chopped parsley, if desired.

Notes

Make sure to slice the butternut squash uniformly to ensure even cooking.
If you prefer a stronger herb flavor, increase the fresh thyme and rosemary slightly.
The Kikkoman® Umami Joy Sauce® adds depth but can be substituted with soy sauce and a splash of Worcestershire sauce for a similar effect.
For a lighter version, substitute half-and-half or reduce the amount of heavy cream.
Use freshly grated cheese rather than pre-shredded for better melting and flavor.
Leftover gratin can be refrigerated and gently reheated in the oven.

Keywords: butternut squash gratin, cheesy gratin, panko topping, autumn side dish, roasted squash casserole, cheesy squash bake