This mushroom leek quiche is a light, filling, and scrumptious egg tart atop a buttery flaky cheddar crust, loaded with layers of veggies. Brimming with flavors of garlic, herbs, and a hint of dijon mustard, this dish is perfect for a weekend brunch or a meatless Monday!
Make extra crusts and use them for meat or pot pies!
This shortbread crust is very easy to make and yields two 8” tarts. I like to make two quiches at a time, one to eat and one to freeze for another day. If you only want to make one then use a 9×13 tart, or jelly roll, tin.
How to Make this Mushroom Leek Quiche
Start by lightly greasing your tart tins. 1 or 2, depending on how many you’re making.
Place the flour, salt, cubed butter, and grated cheese into a food processor then pulse until finely crumbled.
Add a tablespoon at a time of cold water to it and pulse the food processor until a ball of dough is formed.
Divide the dough in half, if making two tarts, and roll each round to fit an 8” prepared tart tin. Once both shells have been rolled out use a fork to pierce holes all over the bottom of the pastry.
Line with parchment paper and pie weights, or rice, and place in a preheated oven to partially bake. After 15 minutes remove the parchment paper and weight and allow shells to bake another 5 minutes.
While the pastry is baking start by adding butter and diced onions to a pan, cook until golden brown. Then add the sliced mushrooms, salt, and pepper. Cook until fork-tender and there is no liquid left in the pan. Remove to a plate then use the same pan for the leeks.
In the same pan add butter, leeks, thyme, salt, and pepper. Cook over medium-high heat, stirring occasionally, until tender and caramelized. While these are cooking you can prep the tart shell and egg mixture for assembly.
Add Dijon, or grainy, mustard to the bottom of each tart shell then use the back of a spoon to spread evenly over the base. Now use half the mushrooms to make a single layer over the pastry, use the other half and repeat this step on the second tart. Last divide the leeks place half in an even layer over one tart and repeat with the other half over the second tart.
To make the egg filling add heavy cream, whole milk, eggs, egg yolks, salt and pepper to a bowl. Use a whisk to whip until while combined and frothy. Use half the egg mixture to evenly pour over the first tart, use the other half and repeat the process for the second tart.
Once both quiche tarts have been filled carefully transfer them to a preheated oven to bake. The centre should be lightly set and slightly browned. Remove tarts from the oven and let cool for 15 minutes before slicing and serving.
This customizable quiche allows you to substitute whatever veggies you’d like! I, personally, think this combination is THE BEST, but you do you!
For the addition of meat if you’d like, you can add diced ham, crumbled bacon, or shredded chicken.
This is a completely healthy and satisfying meal all on its own, but by all means, serve with your favorite sides and enjoy!
cheddar shortcrust pastry
- 2 cups ap flour
- 1 cup cold butter, cubed
- 1/2 cup grated cheddar cheese
- 1/2 tsp salt
- 1/3 cup cold water
- In a food processor add flour, salt, grated cheese, and cubed butter then pulse until finely crumbled.
- Now add the cold water, 1 tablespoon at a time, and pulse between each addition. Add enough water until the dough forms a ball.
- Divide dough in half. Roll one half into a round, 1/4" – 1/2" thick) then place into a lightly greased tart pan, repeat this process with the second round.
- Use a fork to pierce holes all over the bottom of both tart shells. Line with parchment and fill with pie weights then place in an oven preheated to 400 degrees. Bake for 15 minutes then remove parchment and weights return the tarts shells to the oven to bake 5 more minutes. Remove from the oven and allow to cool well filling is assembled.
Mushroom leek quiche tart
- 3 tbsp butter
- 1 large onion finely diced
- 2 cloves garlic, finely diced
- 3/4 lb sliced mushrooms
- 3 large leeks, white part only, thinly sliced
- 5 sprigs fresh thyme
- 2 tbsp grainy, or dijon, mustard
- 3 large eggs
- 2 large egg yolks
- 3/4 cup heavy cream
- 1 3/4 cup whole milk
- 1 tsp salt
- 1 1/2 tsp pepper
- In a large pan, over medium high heat, add 2 tbsps butter and the finely diced onion, cook about 5 minutes until onions are translucent.
- Add the sliced mushrooms into the pan, and add salt and pepper to taste. Continie cooking about 8 more minutes, until mushrooms are fork tender and no liquid remaing in the pan. Remove the mushrooms to a plate and return the pan to the oven.
- Add the remaining 1 tbsp. butter to the pan, the sliced leeks, garlic, and thyme. Cook about 12 minutes, stirring occasionally, until the leeks are tender and golden brown.
- Preheat the oven to 400 degrees. Add 1 tbsp of mustard to the base of the tart shell then spread into an even layer. Repeat the process with the remaining mustard on the 2nd tart.
- Add a single layer of mushrooms to the bottom of each tart shell, now add a layer of leeks on top of the mushrooms. Once both shells have been layered set aside to make the egg filling.
- In a medium bowl add the eggs, egg yolks, salt, pepper, cream, and milk then use a whisk to whip together until frothy and completely combined. Pour half the egg mixture into an even layer in one tart, then use the remaing mixture to fill the second tart.
- Place the prepared quiches into the preheated oven and bake for 25-30 minutes, until the center is set and the center is just starting to brown. Remove from the oven and allow to cool for 15 minutes before slicing and serving