Preheat oven to 350°F (177°C). Place parchment paper over the crust, then top with pie weights (or dried beans). Bake for 20 minutes. Remove parchment paper and pie weights, then return crust to oven and bake until light golden, 5-10 minutes.

Melt butter in a skillet over medium-high heat. Add onions, ¼ teaspoon of salt, and ¼ teaspoon of pepper. Stir to mix. Cover with a lid and cook for 10 minutes, stirring occasionally.

Uncover skillet, add butternut squash and continue cooking until onions are golden brown and squash is tender, 8 to 10 minutes. (If brown bits stick to the skillet, add a bit of water to loosen. Reduce heat slightly if needed to prevent burning.)

Add kale and cook until it softens, about 1 minute. Stir in thyme. Remove veggie mixture from heat and set aside.

In a medium bowl, whisk together eggs, milk, the remaining ½ teaspoon salt, and the remaining ¼ teaspoon pepper.

With the blind-baked quiche set on a baking sheet, layer in the veggie mixture and cheese. Pour the egg mixture over the fillings, until the crust is filled (you may not use it all). Slide the quiche into the oven (on the baking sheet). Bake until the eggs are set but the middle still has a little bit of a wiggle, 30 to 40 minutes.

Let cool before cutting and serving.