This butternut squash quiche has caramelized onions, cheese, and kale. It's a great vegetarian option for the holidays or entertaining. Quiche is make-ahead friendly - and can be served for brunch, lunch, or dinner. Leftovers taste great too! (Gluten Free option)
Blind bake crust: Preheat oven to 350°F (177°C). Place a pie of 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.
Meanwhile, cook onions: Melt butter in a skillet over medium-high heat. Add onions, ¼ teaspoon of the salt, and ¼ teaspoon of the pepper. Stir to mix. Cover with a lid and cook for 10 minutes, stirring occasionally.
Add squash: Uncover skillet, add butternut squash and continue cooking until onions are golden brown and squash is tender, 8 to 10 minutes. (If there are brown bits sticking to the skillet, add a bit of water and stir to loosen. Reduce heat slightly if needed to prevent burning.)
Add kale and thyme: Add kale, cook until it softens, about 1 minute. Stir in thyme. Remove veggie mixture from heat and set aside.
Whisk egg mixture: In a medium bowl, whisk together eggs, milk, the remaining ½ teaspoon salt, and the remaining ¼ teaspoon pepper.
Assemble and bake: 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.
Video
Notes
Gruyere cheese and substitutes: Imported Gruyere cheese typically contains animal-based rennet. If you wish to avoid this, look for labels that say "vegetarian friendly" or lists "microbial enzymes" as an ingredient (instead of rennet). Jarlsberg or Gouda are good substitutes for Gruyere. Or use aged cheddar cheese insteak.
Crust: We recommend a 9-inch (23 cm) tart pan with removable bottom or an 8-inch pie plate. Tart pans tend to have shorter sides than pie plates, so the smaller pie plate diameter helps adjust for this.
Make ahead / reheating instructions: Quiche can be baked in advance, wrapped tightly (once fully cooled), and refrigerated. Reheat at 300°F (150°C) until quiche is warmed through.
Freezing instructions: Let quiche cool completely after baking. Wrap tightly in foil, then place in an extra-large freezer bag. Freeze for up to 2 months. Bake directly from frozen, at 300°F (150°C) until quiche is warmed through.