Dotted with balsamic vinegar caramelized onions, roasted squash and fresh spinach, this quiche is incredibly delicious, yet healthful.
1 yellow onion, or 3 Cipollini onions, peeled
2 tablespoons olive oil, divided
1 tablespoon balsamic vinegar
1½ cups Turk’s Turban squash (or other winter squash of your choice), cut into 1-inch cubes
1 cup whole milk
5 large eggs
1 tablespoon fresh rosemary, minced
½ teaspoon fresh thyme
1 cup grated cheddar cheese
1 cup packed spinach leaves
Sea salt and fresh ground pepper
1 pre-prepared pie crust
1. Preheat the oven to 375°. Roll the prepared crust into a 12-inch circle (to fit a 9-inch pie pan). Prick it all over with a fork. Bake the crust for 10 minutes, then remove from the oven and set aside to cool.
2. To make the filling: Quarter the onion, and slice thinly. Heat 1 tablespoon of the olive oil in a medium saucepan over medium-low heat. Add the onion and cook, stirring occasionally, until caramelized and deep golden brown. (This will take about 20 minutes). Right before the onion finishes cooking, add balsamic vinegar to the pan and cook for a few more minutes. While the onion is caramelizing, spread the cubed squash on a baking sheet and toss it with the remaining olive oil, along with dashes of salt and pepper. Roast the squash until it starts to brown and soften, about 20 minutes as well. In a large bowl, whisk together the milk and eggs. Add the rosemary, thyme, cheese, salt, and pepper to the eggs. Place the caramelized onions, roasted squash, and baby spinach in the pie pan. Pour the egg mixture over the vegetables.
3. While the onion is caramelizing, spread the cubed squash on a baking sheet and toss it with the remaining olive oil, along with dashes of salt and pepper. Roast the squash until it starts to brown and soften, about 20 minutes as well.
4. In a large bowl, whisk together the milk and eggs. Add the rosemary, thyme, salt, and pepper. Add the caramelized onions, roasted squash, grated cheese, and baby spinach. Pour the mixture into the pie crust.
5. Bake the quiche for about 40 to 45 minutes. The edges should be golden brown and the center should feel just set. Remove the quiche from the oven and let it cool on a rack. Serve warm, or at room temperature.