Preheat your oven to 375°F (190°C).

In a large skillet over medium heat, add olive oil. Sauté diced onion, sliced mushrooms, and cubed butternut squash for 5-7 minutes until tender.

Stir in chopped kale and cook for an additional 2-3 minutes until wilted.

In a mixing bowl, whisk together eggs, milk, salt, and pepper until well combined.

Spread the sautéed vegetable mixture evenly into the pie crust. Pour the egg mixture over it, then top with shredded cheese.

Bake in the preheated oven for 35-40 minutes until golden brown and set.

Let cool for 5-10 minutes before slicing and serving warm.