Gruyère Leek Quiche

A classic French quiche, with a tender, decadent custard and flaky crust, is truly exceptional. When paired with a fresh green salad, it easily ranks among my all-time favorite meals.

But let’s be honest, there are a lot of underwhelming and unmemorable quiches out there. This might explain why quiche is often overlooked or underrated.

While my love of quiche runs deep, I’ve yet to share an authentic French quiche recipe. Today, I’m excited to share this fantastic Gruyère Leek Quiche. It features my flaky quiche crust, along with tips I learned in French culinary school and over my years of cooking.

Why You’ll Love This Quiche:

Exceptional Texture: The key to a silky, tender savory custard is to bake it low and slow. This quiche is baked at 325°F (165°C). Proteins (such as eggs) cooked at a low temperature are more tender and retain more fat and moisture. The custard should be just set, but jiggle a tiny bit in the center.
Effortless Reheating: Making quiche from scratch takes time, but here’s the good news – it reheats beautifully! Prepare over the weekend for quick breakfasts and dinners throughout the week. You can make and freeze the quiche crust days, weeks, or even months in advance, cutting time considerably. Get a head start by prepping fillings, such as sautéed vegetables and grated cheese, days ahead.
Adaptable: Make this recipe your own. Swap leeks for other sautéed or roasted vegetables, such as mushrooms, broccoli, asparagus, and more. Add bacon for a Quiche Lorraine twist. Experiment with fresh herbs, such as dill, parsley, or fresh thyme. The key is to use a similar volume and cook down any fresh vegetables to reduce their water content.

Lined Quiche Crust Filled with Beans and Foil

Quiche Components:

Prebaked Crust – using a prebaked shell ensures the crust will maintain its sturdiness and not get soggy when you add the loose custard. This quiche recipe uses my favorite quiche crust recipe, which produces a flaky crust that will not shrink – allowing it to hold a generous volume of custard.
Gruyère Cheese – known for its rich, nutty flavor and meltability, gruyère is my go-to cheese for quiche. An aged cheddar is a good alternative here.
Leeks – sautéed until soft and translucent, leeks are a bit more special than regular onion and nearly melt into the baked custard. If you prefer, you can substitute sautéed shallot, yellow onion, or even green onions.
Egg Custard – this quiche features an egg custard, prepared with the classic ratio of 1 egg: 1/2 cup dairy (heavy cream). Believe it or not, quiche is more cream than egg. This produces an exceptionally silky, smooth filling. I like to add freshly grated nutmeg and a touch of Dijon mustard for added flavor. See notes on dairy substitutions below.

Can I Substitute Heavy Cream with Other Dairy?

While options are great, there’s a reason classic French quiches rely on heavy cream and quite a lot of it. Why? It boils down to dairy fat and its influence on flavor, texture, and mouthfeel.

Heavy cream boasts a fat content exceeding 35%, significantly higher than whole milk’s meager 3.5% fat. This difference matters, particularly for egg custards.

Opting for whole milk or a milk-cream combo is, of course, possible, but will not deliver the best texture or flavor. [Note: This is a classic French quiche, not a light frittata.] Our goal is to make an authentically classic quiche that is exceptional in taste and texture, making the effort and time invested worthwhile.

Still wondering if you can swap the cream for something else? If you insist, you can use half and half, but be prepared for a difference in texture. Please do not use whole milk – this recipe has been tested extensively and it will not produce the desired results.

Storing and Reheating Quiche:

Store leftover quiche in the refrigerator for up to 5 days or freeze (no need to thaw before reheating) for up to 3 months. When freezing, cut into slices, wrap tightly in foil, and place in a Ziplock bag.

To reheat, preheat the oven to 325°F (165°C). Slice the quiche into individual portions (this will speed up the warming process) and set on a parchment-lined sheet pan. Bake for 15 to 25 minutes, depending on size, until heated through. Serve immediately.

Serving Suggestion:

Whether enjoyed at breakfast, lunch, or dinner, I love pairing quiche with a vibrant, leafy green salad. For balance, toss the salad with a bright and acidic vinaigrette, such as this easy lemon vinaigrette. It adds contrast and helps balance the richness of the custard.

Prepared with heavy cream, this Gruyère Leek Quiche boasts an exceptionally tender custard and a flaky all-butter crust.

This recipe utilizes a classic French custard ratio of 1 egg to ½ cup heavy cream (there’s no skimping here!). To ensure success, we’re starting with a prebaked quiche crust (we recommend using this quiche crust recipe) and baking the custard at a low temperature. Proteins (such as eggs) cooked at a low temperature will be more tender and retain more fat and moisture than proteins cooked quickly at a high temperature.

For an ideal pairing, serve this quiche with a leafy green salad tossed with a bright and acidic vinaigrette.

Ingredients

Crust:

Filling:

1 large leek, white and light green parts only (200g) sliced lengthwise and thinly sliced
1 tablespoon (15g) unsalted butter
1 tablespoon (15 ml) extra virgin olive oil
½ teaspoon kosher salt
2 ounces (60g) grated Gruyère cheese

Instructions

1 Note: This recipe requires a 9-inch prebaked quiche crust that is on the deeper side. You can prepare this quiche using a shallow tart or pie pan, but it will most likely not accommodate the full volume of custard prepared in this recipe. You can reduce the custard (using the ratio of 1 whole egg: ½ cup cream) or leftover custard can be baked in a ramekin (to produce a crustless quiche!) at 325°F (165°C) until just set.
2 Preheat the oven to 325°F (165°C) with a rack in the center position. Place the prebaked quiche crust on a rimmed sheet pan and set aside.
3 Sauté the Leeks: In a medium skillet, heat the butter and olive oil over medium-low heat. Once the butter has melted and is lightly bubbling, add the sliced leeks and sprinkle with ½ teaspoon kosher salt. Cook, stirring often, until the leeks are soft and tender, about 10 to 12 minutes. If the pan gets dry and they are beginning to gain color, add a small splash of water as needed. Transfer to a small bowl to cool while you prepare the custard.
4 Prepare the Custard: In a medium bowl, combine the eggs, heavy cream, Dijon mustard, salt, and nutmeg. Whisk until smooth.
5Assemble and Bake: Sprinkle the grated cheese onto the bottom of the prebaked crust. Distribute the sautéed leeks in an even thin layer on top. Pour in the egg custard – it should just about reach the top. Carefully transfer to the oven and bake for 40 to 55 minutes or until lightly golden and the custard is set, but still has the slightest jiggle in the center. Set on a wire rack to cool for 10 to 15 minutes before slicing. Serve warm or at room temperature.