You will thoroughly enjoy this gluten free loaded mashed potato quiche whether you add caramelized onion to the filling, garnish it with the onion, or omit them altogether. The texture of the filling is like nothing you’ve had before and the crust is perfection, tender, yet sturdy enough to remove from the pie dish.
I was in a rush when I made this quiche. I knew I wanted to add caramelized onion for additional flavor, but I didn’t have 45 additional minutes to wait for the onion to be done. So, I made the quiche. Then, while the quiche was baking, I caramelized the onion, which I added to the top of the quiche. You can definitely add the caramelized onion to the filling, but they will sink to the bottom. Just be sure not to add more than specified in the recipe or the filling will overflow.
It’s a good idea to serve the caramelized onion on the sides if you will be serving both adults and children.
You can use plant-based bacon-bits.
Gluten Free Loaded Mashed Potato Quiche
For the Pie Crust:
- 1 recipe Tender Gluten Free Pie Crust
For the Caramelized Onion (For the Filling or Garnish) (Optional):
- 1 medium yellow onion peeled and thinly sliced
- 2 teaspoons olive oil
- 2 teaspoons unsalted butter (or more oil)
For the Quiche:
- 2 cup Loaded Mashed Potatoes
- 1 cup loosely packed shredded cheddar cheese or dairy-free (or half chopped, cooked bacon)
- 1/4 heavy cream or full-fat coconut milk
- 5 large eggs
- 1 cup shredded cheddar cheese or dairy-free substitute*
- 1/4 teaspoon salt
- 1/4 teaspoon ground white pepper (or 1/8 teaspoon)
- Sour cream for garnish (optional)
To Make the Crust:
Make the crust as indicated at the above link. Only par-bake/blind-bake the crust for 15 minutes; set aside to cool. (The crust may be made up to two days prior to making the quiche. Just cover with plastic wrap and leave out at room temperature if serving the following day. Otherwise, cover and freeze. Then, defrost at room temperature prior to filling. For making days in advance without freezing, see the Notes section below.)
To Make the Caramelized Onion:
Add the oil and butter to a 10-inch skillet over medium-high heat. Do not allow to smoke. Add the onion, stir, and lower heat to medium-low, stirring often. Saute for about 45 minutes and set aside.
To Make the Quiche:
Preheat the oven to 350ºF.
In a medium to large bowl, whisk the eggs. Add the loaded mashed potatoes (or mashed potatoes with a little cheese and bacon, plus an additional 1/4 cup heavy cream, sour cream, or cream cheese, totaling 2 cups), cheddar cheese, caramelized onion, if using, salt, and pepper. Whisk everything together and pour into the crust.
Bake on the center shelf of the oven for 30 - 40 minutes or until a knife, cake tester, or toothpick inserted in the center comes out clean. When the crust reached your desired color, cover the edges with foil or a silicone crust ring.
As an option, transfer the pie to about 6-inches from the broiler (on high heat) for about 30 seconds or less or until the filling turns golden brown.
Transfer to a wire rack to cool for about 10 minutes prior to serving. Garnish with a little sour cream, caramelized onion if you didn't add it to the filling, and/or snipped chives.
Slice and serve with a salad or a vegetable of your choosing.
*Follow Your Heart Cheddar Shreds is a great brand of dairy-free and vegan cheese. Alternatively, use Daiya. To make two to three days in advance, without freezing, fully bake the crust as indicated in the crust recipe, fill it and bake it as directed above. Cool and cover with plastic wrap. The crust will turn out perfectly by the second day. If you serve it the same day, the crust will be too dry.