Give shredded zucchini a good squeeze to extract as much water as possible. I do it by placing zucchini into a linen towel and wringing into a ball (save the liquid for soup or smoothies). Transfer to a medium bowl and set aside.
Preheat oven to 400 degrees F and spray 9" pie dish with cooking spray (I used tart pan lined with parchment). In a medium bowl, add eggs and whisk.
Add flour and whisk well to combine (it will take a few minutes). Add both cheeses, salt and pepper, and whisk one more time.
To the bowl with zucchini, add chives and mix with spatula. Then pour egg flour mixture on top and stir well to combine.
Transfer mixture to previously prepared baking dish and bake for 45 minutes or until toothpick inserted in the middle comes out clean.
Broil for a few minutes for a golden crust. Cool off a bit, cut into 8 slices and enjoy warm or cold (I love cold quiche!).
Notes
Make ahead quiche mixture and refrigerate for up to 1 day. After bake as per recipe. If you need to make quiche ahead 2 days in advance, you can prep zucchini and store with chives. And grate cheeses and refrigerate separately. Helps a lot!
Store: Leftovers for up to 5 days covered.
Reheat quiche? I love mine cold. It is so good! If you must, I recommend a microwave otherwise it will dry out in the oven.
Air fryer: Line air fryer basket with unbleached parchment paper and spray well with cooking spray. Add mixture, level with spatula and bake in preheated air fryer to 320 F degrees for 30 minutes. Do toothpick test in the center for doneness.