Caramelized Onion and Roasted Butternut Squash Quiche
Quiche is one of my favorite dishes to prepare for Sunday brunch. It’s savory, elegant, and extremely versatile. Most often I use whatever vegetables I have on hand as inspiration for the filling, and honestly it’s hard to go wrong with cheesy eggs, herbs, buttery crust, and seasoned veggies. Plus leftovers make an easy and nourishing breakfast for busy workdays.
A few tips for a successful quiche: first, make the crust dough in advance, and let it rest in the refrigerator for at least a day. Pie dough is basically an ornery toddler. It needs it’s time to rest and chill, and it doesn’t like to be rushed. If you try to rush it, the dough will tantrum and be unbearably difficult to shape. Once a dough tantrum hits, it’s very challenging to recover, and the bake often ends up tough instead of tender and flaky.
Making the crust in advance also allows you to break up the effort of making a quiche. All pies are a bit onerous with several steps and a longer bake. I prefer to break up the steps as much as possible so that the morning we enjoy the quiche is pretty much just assembly and baking. If this is your goal, you can sauté the onions and roast the squash a day in advance.
Finally, you can use this recipe as a jumping off point for quiches with other vegetables and cheeses. If squash isn’t your favorite, you can replace it with broccoli, mushrooms, carrots, or any you love. The biggest thing to keep in mind is the vegetable water content. If you use tomatoes, make sure that you roast or sauté them in advance to reduce the water they release while baking. This will prevent your custard from being too watery and not setting properly.
Savory All Butter Crust
Equipment:
Food processor
9in pie dish
Ingredients:
1 1/2 cups all-purpose flour
1/2 tsp kosher salt
1 stick cold unsalted butter, cubed
3-4 TBS. cold water
Method:
Pulse the flour and salt together in a food processor a couple of times to mix.
A few cubes at a time, add the butter to the flour mixture, pulsing in between each addition. Continue until all the butter is added and the mixture takes on a sand-like texture.
Add the water a tablespoon at a time, pulsing several times between each addition. Pulse until the dough begins coming together in a ball. Only add the 4th tablespoon if the dough is too dry to come together.
Remove the dough, form it into a disk, and wrap in plastic wrap. Store the dough in the refrigerator for at least 2 hours, but preferably overnight or a couple days before baking.
Preheat the oven to 375ºF.
Remove the dough from the refrigerator and allow it to warm up for about 20 minutes. On a lightly floured surface roll out the dough into a round that’s slightly larger than your pie dish. Transfer the round to your dish and gently press the dough down evenly along the bottom and walls of the dish. Fold the edges under themselves and crimp or shape the edges in your preferred method.
Par bake the crust. Prick the bottom all over with the tines of a fork, line the crust with parchment paper and baking beans, and then bake in the preheated over for 15 minutes. Remove from the oven and take out the parchment paper and beans and allow the crust to cool.
Caramelized Onion & Roasted Butternut Squash Quiche
Ingredients:
I par baked Savory All Butter Crust
1 TBS. + 2 tsp. olive oil
Scant 2 cups or 265g butternut squash, peeled and cut into 1/2 inch cubes
1 cup chopped spinach and/or kale
1 yellow onion, sliced
2 cloves garlic, minced
1 tsp kosher salt, divided
1/2 tsp. black pepper
1/2 tsp. fresh thyme, chopped
1 TBS. fresh rosemary, chopped
1 cup shredded mild cheddar
5 large eggs + 1 egg, beaten for egg wash
3/4 cup whole milk
Additional squash and rosemary for blossoms (optional)
Method:
Preheat the oven to 400ºF.
Toss the cubed butternut squash, 2 tsp. of olive oil, and 1/4 tsp. kosher salt together. Pour into a rimmed baking sheet or casserole dish and bake for 20 minutes until the squash is softened and lightly browned. Remove from the oven and allow to cool. Lower the oven to 375ºF.
Meanwhile caramelize the onions. Heat the remaining 1 TBS. olive oil in a fry pan over medium low heat. Add the onions and stir, then cover the pan and continue to cook for about 20 minutes. Stir the onions regularly. After 20 minutes, the onions should be golden and fragrant, but not blackened. Add the garlic to the onions and cook for one or two minutes more. Then add the spinach/kale and 1/4 tsp kosher salt, and cook until the greens are wilted. Remove the pan from the heat and allow to cool while you make the egg custard.
In a medium bowl whisk the eggs, milk, 1/2 cup of cheese, remaining 1/2 tsp. kosher salt, pepper, rosemary, and thyme. If using make the squash blossoms. Use a vegetable peeler to peel several long strip of squash. Roll these up like a rug to make little rosettes.
Assemble the quiche. Pour the onion and spinach mixture into the bottom of the prepared crust and spread evenly. Top with 1/4 cup of cheese. Next add the roast squash and spread it evenly. Top the squash with the remaining 1/4 cup of cheese. Finally pour the egg custard mixture over the vegetables. If using arrange the blossoms and a few rosemary springs decoratively on the center surface of the custard.
Bake at 375ºF for 30 minutes. Remove the quiche, brush the egg wash evenly around the crust, and return to the oven for 10-15 minutes or until the crust is nicely browned and the custard is set. Allow the quiche to cool before cutting and serving.
Recipe adapted from King Arthur Baking
