Preheat your oven to 375 degrees. Lay your defrosted (or homemade rolled out pastry dough) into your pie plate. Using your fingers, crimp the edges, or prick the edges all over with a fork. Prick your pie dough with a fork on the bottom. Add pie weights and bake for about 8 to 10 minutes. Remove from the oven and set aside.
While you are par-baking the pie dough, prep your veggies. Place the butternut squash cubes and kale on a lined baking sheet and lightly drizzle olive oil and season with salt and pepper. Bake in the oven for 8 to 10 minutes, or when the kale has become crispy but not burnt. Remove the kale from the oven and onto a plate and place the butternut squash back in for another 10 to 15 minutes.
Using a large bowl, whisk together the eggs, and add in the nutmeg (if using), the heavy cream and season with a little salt and pepper. Add in the roasted butternut squash, the crispy kale, the sautéed mushrooms, half the bacon and all the cheese. Mix well.
Carefully pour quiche batter into your par-baked pie crust and scatter the remaining bacon over the top. Bake in your pre-heated 375 degree oven for about 40 to 45 minutes, or until golden brown and fully cooked through. If you notice the edges of your crust getting too browned, place some foil around the edges only. Remove the quiche from the oven and let it cool on a rack. Serve warm, or at room temperature, with some balsamic glaze if desired. Enjoy!