Prepare the vegetables first. Cut the leeks in half lengthwise and trim the fibrous green tops, leaving the white and tender green parts. Wash them carefully to remove any sand between the layers. Cut them into 1/4-inch slices.
Heat a small skillet over medium heat and melt the butter. Add the leeks and cook until they are slightly tender and bright green. Set aside to cool.
Trim any tough ends from the asparagus.
Fill a shallow pot or large skillet with two inches of water. Bring to a boil and add a heaping tsp. of salt.
Place the asparagus in the pot to cook for about two minutes, or until bright green and barely tender. Immediately plunge cooked asparagus into ice water to cool. Drain well and cut into 1/2-inch pieces, reserving some of the tips to decorate the quiche.
To make the crust, mix the Keto Chow and almond flour together in a large bowl.
Cut the butter and cheese into the flour until the mixture resembles coarse sand with a few pebble-sized pieces of butter still visible.
Add the egg white and one Tbsp. of water and mix until the dough starts to come together. When you pinch the dough between your finger and thumb, it should hold together. If it doesn’t, add the second Tbsp. of water and knead together.
Shape the dough into a ball; wrap it in plastic and let it rest for about 5 minutes.
Sprinkle some Keto Chow on the dough and flatten it into a disc.
Place the disc between two pieces of parchment paper and roll the dough out to approximately 10” in diameter to fit into the tart pan. If it starts to stick, sprinkle more Keto Chow as you work.
Remove the top parchment paper and flip the rolled crust over into the tart pan. Remove the other piece of parchment paper and gently press the crust into the pan, making sure it fits into the edges and the flutes, pinching together any tears or weak spots. Use your rolling pin or your hands to remove any excess crust hanging over the edges of the tin.
Place the tin on a baking sheet and prick about four air vents in the crust with a fork. Don’t make too many or the filling will leak.
Preheat the oven to 375℉, set a rack to the bottom third of the oven, and chill the crust for 20 minutes.
Bake the crust for approximately 20 minutes until it starts to look golden. If it puffs up while baking, gently press it back down to release the steam.
Remove it and set aside while you make the filling, but keep it in the pan and on the sheet tray.
Mix the eggs and egg yolk, then beat in the heavy cream, salt, nutmeg, white pepper, and cayenne.
Spread the leeks, asparagus, and ham (if using) over the crust. Spread the cheese evenly over the vegetables, then gently pour the egg mixture over the fillings. Decorate the top with the reserved asparagus tips.
Place the quiche, still on the baking tray, in the oven and bake for about 20 minutes, or until golden brown and puffed in the center.
Once cooked, allow to cool at least 30 minutes before removing the quiche from the tart pan by loosening the edges and popping the bottom out of the pan.
Serve warm or keep tightly wrapped in the refrigerator for up to five days.