Scalloped Butternut Squash with Caramelized Onions -Thinly sliced butternut squash is enveloped in a sea of caramelized onions and garlicky cream sauce. This side dish is loaded with amazing aroma and delicious flavors. #glutenfree #realfood #holidays
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4.72 from 7 votes

Scalloped Butternut Squash with Caramelized Onions

Thinly sliced butternut squash is enveloped in a sea of caramelized onions and garlicky cream sauce.  
Course Side Dish
Cuisine American
Prep Time 20 minutes
Cook Time 1 hour
Resting Time 5 minutes
Total Time 1 hour 20 minutes
Servings 10 servings
Calories 263kcal
Author Anya


  • 3 tablespoons butter
  • 2 tablespoons avocado oil or another neutral, high-heat oil
  • 1 large onion sliced
  • 4 garlic cloves
  • 4-5 sprigs of fresh thyme OR 1 tablespoon dried thyme
  • 2 teaspoons sea salt
  • 1/2 teaspoon black pepper
  • 1 1/2 tablespoons tapioca starch
  • 2 cups heavy cream
  • 1 small butternut squash


  • Preheat oven to 350 F degrees and butter a 5X8 deep casserole dish. Set aside.

Onion Cream Sauce

  • Melt butter and oil in a large skillet over medium heat. Add sliced onions and season with salt to release juices. Cook, stirring occasionally. 
  • Caramelize onions until they are golden brown, stirring occasionally. (approximately 25 minutes)
  • Add garlic, thyme (fresh or dried), and season with salt and pepper. 
  • Reduce heat to low-medium. Add tapioca and quickly coat onion mixture.
  • Add half & half and whisk to combine everything, keeping heat at low-medium. Cook and whisk occasionally for approximately 5 minutes. Sauce should slightly thicken. 

Preparing Butternut Squash

  • Peel butternut squash and cut lengthwise. Remove seeds and pith. 
  • Thinly slice crosswise creating half moons. 

Scalloped Butternut Squash

  • Spoon 1/3 of the onion cream mixture to the bottom of the casserole dish. Arrange butternut squash slices. 
  • Pour remaining onion cream mixture, creating pockets between the pan sides and slices to allow the sauce to drip through. 
  • Bake uncovered for 40 minutes in the middle rack. Allow to rest for 5 minutes for sauce to settle before cutting into it. 



Depending on the size of the butternut squash, you may want to line the bottom oven rack with a piece of foil to catch any overflow from the cream.


Calories: 263kcal | Carbohydrates: 12g | Protein: 1g | Fat: 23g | Saturated Fat: 13g | Cholesterol: 74mg | Sodium: 516mg | Potassium: 320mg | Fiber: 1g | Sugar: 2g | Vitamin A: 8795IU | Vitamin C: 17.9mg | Calcium: 74mg | Iron: 0.6mg