Some cooked vegetables, a few eggs, butter and flour...and a little bit of fairy dust. Humble ingredients like onions, spinach, and potatoes shine in this comforting, nutritious spinach and onion quiche.
In a food processor, add the flour and salt and pulse once or twice to incorporate. Add the butter and pulse until the ingredients are just mixed, but coarse; it will resemble cornmeal.
With the blade running, add about 1/4 cup of ice water, and then water 1 tbsp at a time until the dough just comes together into a ball (or two, as mine did). It will be slightly sticky.
Dust a clean surface with flour and dump the dough onto the flour. Pat into a disk and wrap in plastic wrap. Refrigerate until chilled through, about 30 minutes, or as long as 3 days.
While the dough is chilling, prepare the caramelized onions. Put a skillet over medium heat. Add the avocado oil and heating until shimmering, then add the butter and heat until melted. Add the onions, thyme, and a pinch of salt and cook over medium heat until the onions are brown throughout and caramelized, 25-40 minutes.
Preheat the oven to 425. Roll out the pastry dough to 1/4" thickness with a circumference rougher 3" wider than your pie plate. Place the dough, centered, over the pie plate and then fold the edges in towards the center of the dish, making the side double the thickness of the bottom. Smooth our the sides and the seams, but don't overhandle the dough. Crimp the edges with your fingers or a fork. With the tines of a fork, prick the bottom all over. Parbake the crust for 10 minutes.
While the crust is baking, sauté the spinach. Transfer the caramelized onions to a small bowl and then use the leftover fat (you only need a tiny amount) to gently sauté the spinach until soft and most of the moisture has steamed, about 8 minutes.
Once the crust is finished parbaking, lower the oven temperature to 350 and prepare the quiche. Sprinkle 1/4 cup of parmesan into the crust. Layer the caramelized onions on top of the cheese, and the sprinkle another 1/4 cup on top of the onions. In the bowl you used for the onions, gently beat the eggs with the half and, paprika, and salt and pepper to taste (I didn't add extra salt because I salted both the onions and the spinach, and used 1/2 tsp pepper). Fold in the cooked spinach.
Pour the egg mixture into the pie crust on top of the cheese and onion layers. Don't mix.
Bake until the eggs are solid, but still a little jiggly in the center, 40 minutes to an hour, depending on the depth of your pie plate. My spinach and onion quiche took 50 minutes, as it's a fairly deep dish. Allow to cool 10 minutes, then cut into wedges and serve.
Spinach and Onion Quiche https://oursaltykitchen.com/spinach-and-onion-quiche/