Butternut Squash Cheddar Gratin with Rosemary Breadcrumbs

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This Butternut Squash Cheddar Gratin has an amazing rosemary breadcrumb topping.

serving Butternut Squash Cheddar Gratin

You’ve probably made plenty of butternut squash in your time, but this one is a little bit different. It’s a delicious butternut squash and sweet onion mixture. And I love the crunchy cheesy topping that’s baked on top. It’s the perfect side dish addition to a Thanksgiving or Christmas meal.

I first made this Butternut Squash Cheddar Gratin recipe (originally spotted in an older Bon Appetit) over ten years ago. I brought it as my contribution to Thanksgiving at a relative’s house. And it was very well received. Everyone loved this slightly different take on roasted butternut squash.  It’s delicious!

Butternut Squash and Onions preparing gratin

How to make Butternut Squash and Cheddar Gratin:

The first thing you’ll do is sauté butternut squash and onions in a large skillet with butter, a little sugar, salt and pepper. That’s all cooked together just until the mixture becomes slightly caramelized. Next, you’ll transfer that mixture to a 9×13-inch casserole dish. At this point, a little broth is drizzled on top, the dish is covered with foil, and it bakes for about 45 minutes.

adding breadcrumb topping to Butternut Squash Gratin

 After baking 45 minutes, you’ll remove the foil and add the topping. It’s a mixture of Panko breadcrumbs, sharp white cheddar cheese, fresh rosemary and dried thyme.

Butternut Squash Cheddar Gratin

Then the gratin is baked until golden- about 30 more minutes.

Note about butternut squash:

You can peel and cut fresh butternut squash and scrape the seeds out. Then chop it.  I do this all the time, but it can be a bit tricky.  There are many markets (Costco too) that sell butternut squash already peeled and cut. This is an easier way to make this recipe.  If you buy it already cut, you’ll need about 4 1/2 cups of fresh chopped butternut squash. Do not use frozen for this recipe.

serving Butternut Squash Cheddar Gratin

Make ahead tip:

Making a holiday meal can be hectic, so whatever you can do ahead of time makes things so much easier! In this Butternut Squash Cheddar Gratin recipe, you can prepare the butternut squash and onion mixture fully up until before you add the topping. At this point, refrigerate the roasted butternut squash and onion mixture. Then (right before you add the topping), warm the butternut squash mixture in the oven. The topping can be added once it’s warmed, and you can continue with the instructions from there.

One serving of Butternut Squash Cheddar Gratin

Those cheddar- rosemary breadcrumbs on top are what really make this recipe so delicious. And that buttery, roasted butternut squash combined with the sweet onions makes for a delicious base for the gratin. Enjoy!

If you are looking for more butternut squash recipes, you might like to try:

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Butternut Squash Cheddar Gratin with Rosemary Breadcrumbs

Fantastic fall side dish!
Prep Time 30 minutes
Cook Time 1 hour 35 minutes
Servings 10 servings
Calories 243kcal
Course Side Dish
Cuisine American
Keyword butternut squash, butternut squash gratin



  • 1/4 cup (1/2 stick) unsalted butter
  • 2 medium sweet onions, peeled and thinly sliced
  • 2 1/2 pounds butternut squash (peeled and seeded), cut into 1/2-inch cubes
  • 1 teaspoon granulated white sugar
  • 1/2 teaspoon salt
  • 1/2 teaspoon freshly ground black pepper
  • 1/2 cup low sodium chicken or vegetable broth


  • 2 cups Panko breadcrumbs
  • 2 cups packed grated sharp white cheddar cheese
  • 1 tablespoon chopped fresh rosemary
  • 1/2 teaspoon dried thyme


  • Preheat the oven to 350°F. Butter a 13x9x2- inch glass baking dish.
  • Melt the butter in large skillet over medium- high heat. Add the onions; sauté until the onions are lightly browned, about 8 minutes (be sure to tend to them and stir every couple of minutes to prevent burning). Add the butternut squash; sauté 4 minutes. Sprinkle the sugar, salt and pepper over the vegetables; sauté until the onions and squash begin to caramelize, about 5 minutes.
  • Spread the vegetable mixture in the prepared dish. Pour the broth over. Cover tightly with foil and bake 45 minutes. (Squash mixture can be made 1 day ahead. Cool, then cover and refrigerate. Reheat in 350°F. oven until heated through, about 10 minutes).
  • Increase the oven temp. to 400°F. In a medium bowl, combine the Panko, cheese, rosemary and thyme. Sprinkle over the gratin. Bake uncovered until top is golden brown and crisp, about 30 minutes.


  • *If you can purchase pre- cut butternut squash (avail. at Trader Joes, Costco and some regular markets), it makes this recipe much easier. Don't use frozen squash.
  • To prepare this recipe GLUTEN FREE, use GF Panko breadcrumbs, and make sure the brand of broth you use is known to be GF.
  • To prepare this recipe as vegetarian, use vegetable broth.


Serving: 1serving | Calories: 243kcal | Carbohydrates: 25g | Protein: 9g | Fat: 13g | Saturated Fat: 8g | Cholesterol: 36mg | Sodium: 354mg | Potassium: 487mg | Fiber: 3g | Sugar: 5g | Vitamin A: 12429IU | Vitamin C: 26mg | Calcium: 248mg | Iron: 2mg

serving Butternut Squash Cheddar Gratin


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  • Claudia wrote:

    I need ideas to refresh my menu.I think this page will help me so much.

  • Matt wrote:

    This recipe is fantastic. I made it over the holidays exactly as you indicated, and the finished product was nothing short of extraordinary. On top of the great taste, the wonderful Rosemary/Thyme/Cheese aroma accompanying the 2nd portion of the baking was heavenly. Needless to say, the 9×13 Pyrex container didn’t need much cleaning by the time it made its way to the sink.

  • Laurie wrote:

    I’m going to bring this to my MIL’s for Thanksgiving! Looks divine!!