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This hearty, cheesy Keto Caramelized Onion and Gruyère Quiche transforms brunch into a gourmet experience without the carbs. The almond flour crust creates a nutty foundation for the rich, custard filling studded with sweet caramelized onions and perfectly melted Gruyère cheese.
I first created this quiche when hosting a brunch for friends with varying dietary needs. The keto followers were thrilled to have something substantial they could enjoy, while everyone else was too busy savoring the rich flavors to notice it was low-carb. Now it's requested at every gathering.
Ingredients
- Almond flour: Provides a nutty flavor and perfect texture while keeping carbs minimal; look for blanched variety for the smoothest result
- Garlic powder: Adds savory depth to the crust that complements the filling beautifully
- Salt: Enhances all the flavors without being obvious
- Butter: Binds the crust and adds richness; use unsalted for better control of the final flavor
- Butter: For caramelizing the onions; provides a velvety texture and rich mouthfeel
- Onion: Transforms into sweet caramelized perfection as the star ingredient; choose yellow or sweet onions for best results
- Gruyère cheese: Offers complex nutty flavors that elevate this quiche beyond ordinary; use aged Gruyère for more pronounced flavor
- Eggs: Create the custard base that holds everything together; farm fresh makes a noticeable difference in color and flavor
- Heavy cream: Produces silky smooth custard texture without requiring flour as a thickener
- Salt and pepper: Balance and enhance the natural flavors of the other ingredients
Step-by-Step Instructions
- Prepare the Crust:
- Combine the almond flour, garlic powder, and salt in a medium bowl, whisking thoroughly to distribute the seasonings evenly. Pour in the melted butter and mix until the texture resembles coarse crumbs. The mixture will seem somewhat loose but will hold together when pressed. Transfer the mixture to a 9-inch pie dish and press firmly against the bottom and up the sides, creating an even layer about ¼-inch thick. Use a flat-bottomed glass to compress the bottom, ensuring it will hold together during baking. Crimp the edges for a professional look and prick the bottom several times with a fork to prevent bubbling. Bake at 325°F for 10-12 minutes until the edges begin to turn golden brown.
- Caramelize the Onions:
- Melt butter in a large skillet over medium-low heat until it begins to foam. Add the thinly sliced onions, spreading them out evenly. Season with a pinch of salt to help draw out moisture and stir frequently for the first 5 minutes. Reduce heat slightly and continue cooking for 15-20 minutes, stirring every few minutes to ensure even browning. The onions should gradually transform from white to golden to a deep amber color. They are done when very soft and deeply caramelized but not crispy or burnt. This slow process is crucial for developing the sweet, complex flavors that make this quiche extraordinary.
- Assemble the Quiche:
- Spread the caramelized onions evenly across the bottom of the cooled crust, distributing them with a spoon to ensure every bite will contain some. Sprinkle half of the grated Gruyère evenly over the onions, allowing some to fall between the onion pieces. In a separate bowl, whisk together the eggs and heavy cream until completely combined and slightly frothy, then season with salt and pepper. Carefully pour this mixture over the onions and cheese, filling the crust nearly to the top. Sprinkle the remaining Gruyère over the surface, which will form a beautiful golden crust during baking.
- Bake to Perfection:
- Place the quiche on the middle rack of the oven and bake at 325°F for 35-40 minutes. Look for a slight jiggle in the very center when gently shaken; the edges should be set but the middle should have minimal movement. The top should be golden brown and the cheese melted and bubbling. Remove from the oven and allow to rest for at least 15 minutes before slicing. This resting period is crucial as it allows the custard to fully set and makes for cleaner slices.
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The caramelized onions are truly the soul of this recipe. I discovered their transformative power years ago when I accidentally left onions cooking longer than intended. What seemed like a mistake turned into culinary magic as they developed a complex sweetness that balanced perfectly with the nutty Gruyère. My husband now requests this quiche for special occasions and even birthdays instead of cake.
Storage and Make-Ahead Tips
This quiche stores exceptionally well in the refrigerator for up to 4 days. Cover tightly with plastic wrap once completely cooled. For best results when reheating, allow slices to come to room temperature before warming in a 300°F oven for about 10 minutes. The quiche can also be frozen whole or in individual slices. Wrap tightly in plastic followed by foil and freeze for up to 3 months. Thaw overnight in the refrigerator before reheating. The crust may lose some crispness after freezing but the flavor remains outstanding.
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Perfect Pairings
This quiche works beautifully as the centerpiece of a keto brunch when paired with complementary sides. Serve alongside a simple arugula salad dressed with lemon and olive oil to cut through the richness. For non-keto guests, offer a basket of crusty bread. This quiche also transitions easily to dinner when served with roasted asparagus or brussels sprouts. A glass of dry white wine like Sauvignon Blanc or a light Pinot Noir complements the caramelized onions and nutty cheese wonderfully.
Customization Options
While this recipe is perfect as written, it welcomes personalization. Replace up to half the Gruyère with another cheese like sharp cheddar or fontina. Add cooked and crumbled bacon or pancetta for a smoky dimension. Fold in fresh herbs like thyme or chives for brightness. For a vegetable boost, add sautéed mushrooms, spinach, or roasted red peppers. Just be sure to cook off any excess moisture from vegetables before adding them to prevent a soggy quiche.
Frequently Asked Questions
- → How can I ensure the onions caramelize properly?
Cook the onions over medium-low heat, stirring frequently, and avoid rushing the process. This allows their natural sugars to develop a deep, sweet flavor.
- → Can I substitute the almond flour crust?
Yes, you can use other low-carb alternatives such as coconut flour or a cauliflower crust, but they may alter the flavor and texture.
- → What's the best way to tell if the quiche is done baking?
The center of the quiche should be set but still have a slight jiggle. Let it rest for 15 minutes out of the oven before serving for easier slicing.
- → Can I make this dish ahead of time?
Yes, you can prepare the quiche in advance. Store it in the refrigerator for up to 3 days and reheat in the oven before serving.
- → Can I use a different cheese instead of Gruyére?
Yes, you can substitute Gruyére with Swiss cheese or even a sharp cheddar for a slightly different flavor profile.
- → Can this quiche be frozen?
Absolutely! Allow the quiche to cool completely, then wrap tightly in plastic wrap and foil before freezing. Thaw and reheat in the oven when ready to serve.