Crustless Zucchini & Parmigiano Quiche
Preheat the oven to 400°F.
Butter pie plate, skillet, or oven proof ramekin, dust with breadcrumbs. Set aside.
Melt the butter and olive oil in a pan. Add the onion slices and sprinkle a bit of salt and pepper over them. Cook the onions over medium heat until they are translucent, just taking on a little bit of color. Add the zuccini and summer squash to the pan, add a pinch more salt. Add the sage. Cook until the squash has released all of its liquid and the mixture has cooked the liquid off. Add the lemon zest and mix thoroughly.
Remove the pan from the heat to cool.
While the squash mixture is cooking: In a bowl, beat the eggs thoroughly. Add the milk, cheese, 1 teaspoon of salt, and 1/2 teaspoon of pepper, and nutmeg. This is a savory custard mixture. Pour the half of the custard into the pie dish. Add the squash mixture to the custard in the pie dish, ensuring that it is evenly distributed. Cover with the remaining custard. Grate a little extra Parmigiano on the top of the custard.
Transfer the quiche to the oven and bake for 30 — 45 minutes. Once the surface is lightly brown all the way across, and the center does not jiggle it’s fully cooked. Let the quiche cool for about 20 minutes, then slice into wedges.