Go Back Email Link
+ servings
featured image for Butternut Squash Gratin

A Butternut Squash Gratin With Parmesan And Rosemary

As butternut squash roasts, naturally occurring sugars caramelize with heat resulting in a gorgeous golden ochre color, its flavor earthy and sweet.
Print Recipe Pin Recipe
Prep Time: 15 minutes
Cook Time: 1 hour
Total Time: 1 hour 15 minutes
Course: Side Dish
Cuisine: American
Keyword: butternut squash, butternut squash casserole, butternut squash recipes mashed, christmas sides, how to make butternut squash, make butternut squash, mashed squash, Thanksgiving sides
Servings: 4 servings
Calories: 294kcal
Cost: $0.89 per serving

Want a bigger or smaller serving size? Hover over the serving size and move the bar until you get the number of servings you want. Easy.


  • vegetable peeler
  • Sharp Kitchen Knife
  • cutting board
  • large mixing bowl
  • baking dish


Ingredients For A Butternut Squash Gratin With Parmesan And Rosemary

  • 1 large butternut squash peeled, seeds removed, and cubed into 1/2-inch cubes
  • 2 tablespoons olive oil
  • 2 tablespoons salted butter
  • 1/2 cup sweet onion finely chopped
  • 6 cloves garlic smashed and chopped
  • 1/2 cup Parmesan freshly grated from a block, not from a can
  • 1 tablespoon lemon zest fresh
  • 3 tablespoons rosemary fresh, finely minced
  • 1 tablespoon parsley fresh, finely minced
  • 1/2 cup panko
  • 1 teaspoon, or more to taste Malden salt or other flakey sea salt
  • to taste black pepper freshly ground


The Method

  • Preheat oven to 350°F. Use a pastry brush to lightly coat the bottom and sides of a casserole dish. Set aside.
  • Peel the butternut squash (see my method for ease of peeling above). Slice in half lengthwise and scoop out seeds from the bulbus end of both halves. Cut into 1/2-inch thick slices, then into 1/2-inch cubes. Add to a large mixing bowl and set aside.
  • In a large non-stick skillet, sauté the finely chopped onion and the chopped garlic for 3 to 5 minutes over medium-high heat. You want the onion first translucent, but then to turn golden. Avoid allowing the garlic to burn by constantly moving the mixture around in the pan.
  • In a medium sized mixing bowl, combine the panko, grated parmesan, lemon zest, finely chopped rosemary, and finely chopped parsley and stir well to combine. Spoon enough of the garlic butter mixture into the panko mixture and stir until well combined, about 2 tablespoons.
  • Scrape the remaining garlic butter mixture into the cubed squash. Use a wooden spoon or rubber spatula to combine and coat all of the squash well. Turn out into the prepared baking dish. Arrange so the squash is evenly distributed from side to side. Season with the Malden salt and the black pepper.
  • Scrape the panko gremolata over the squash cubes. Use the tines of a fork to lift some of the cubes allowing the gremolata to fall between the crevasses of the squash.
  • Bake uncovered for 1 hour or until the squash cubes are sufficiently tender and the panko gremolata has turned a beautiful ochre color.
  • Serve immediately with additional fresh rosemary if desired.


Please Note that table salt and iodized salt are NOT substitutions for Kosher salt. Do not use table salt or iodized salt in any of the recipes you find on Not Entirely Average UNLESS specified otherwise. This recipe calls for Malden salt which is a flakey sea salt. If you are unable to locate Malden, use Kosher.
Substitute pre cubed fresh squash for whole fresh squash. Do not use frozen squash in this recipe.
Make ahead the actual squash up to two days in advance; peel, de-seed, and cube only, do not cook/bake the squash until the day it will be served. Panko gremolata must be made the day the gratin will be served.
Freezing Not Recommended this dish does not maintain its flavor or integrity once frozen. Refrain from freezing both before and after table service.


Serving: 1serving | Calories: 294kcal | Carbohydrates: 32g | Protein: 8g | Fat: 17g | Saturated Fat: 7g | Polyunsaturated Fat: 1g | Monounsaturated Fat: 8g | Trans Fat: 1g | Cholesterol: 24mg | Sodium: 794mg | Potassium: 752mg | Fiber: 5g | Sugar: 6g | Vitamin A: 20336IU | Vitamin C: 46mg | Calcium: 289mg | Iron: 2mg

Please note that the nutrition information provided above is approximate and meant as a guideline only.