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Autumn Butternut Squash and Caramelized Onion Frittata

This frittata features tender eggs baked with roasted butternut squash and sweet, caramelized onions. It has a fluffy, custardy interior with crispy, browned edges, offering a warm, rustic appearance suitable for a cozy breakfast or brunch.
Prep Time 15 minutes
Cook Time 30 minutes
Total Time 45 minutes
Servings: 4
Course: Main Course
Cuisine: American
Calories: 250

Ingredients
  

  • 1 lb butternut squash peeled and cubed
  • 2 large onions thinly sliced
  • 6 large eggs
  • 1/4 cup milk optional, for fluffiness
  • 2 tablespoons olive oil divided
  • to taste salt and pepper for seasoning

Equipment

  • Mixing bowl
  • Frying pan
  • Oven-safe skillet or baking dish
  • Knife
  • Cutting board
  • Whisk

Method
 

  1. Preheat your oven to 400°F (200°C). Toss the cubed butternut squash with 1 tablespoon of olive oil, salt, and pepper, then spread evenly on a baking sheet. Roast until tender and lightly caramelized, about 20-25 minutes, filling your kitchen with a sweet, nutty aroma.
  2. Meanwhile, heat the remaining 1 tablespoon of olive oil in a large oven-safe skillet over medium heat. Add the sliced onions and cook slowly, stirring occasionally, until they soften and turn golden brown, about 10-15 minutes. They should smell sweet and deepen in color.
  3. Once the onions are caramelized, add the roasted squash to the skillet and gently fold them together. Let the mixture cook for another 2 minutes so flavors meld and the edges start to crisp slightly.
  4. In a mixing bowl, whisk together the eggs, milk (if using), salt, and pepper until smooth and slightly frothy. This creates a custardy base for the frittata.
  5. Pour the egg mixture evenly over the squash and onions in the skillet. Let it sit without stirring for about 30 seconds, allowing the eggs to start setting at the edges.
  6. Transfer the skillet to the preheated oven and bake until the eggs are puffed and just set, approximately 12-15 minutes. The top should be lightly golden and slightly crisp at the edges.
  7. Remove the skillet from the oven and let the frittata rest for a few minutes. The edges will be beautifully browned and bubbling, while the center remains soft and tender.
  8. Slice the frittata into wedges and serve warm. The contrast of crispy edges and fluffy interior makes each bite satisfying and rustic.

Notes

For extra flavor, sprinkle fresh herbs like thyme or parsley before serving. You can also add grated cheese for a richer version.