The making of mushroom quiche is a labor of love, but it really is a treat well worth the effort. The smoky cumin-flavored caramelized onions enfolded in a delicately textured custard set in buttery, tender, and crisp crust trick you into eating far more than you should. 

But as I always say, a little pre-planning and there is no reason you can’t have a quiche anytime. Break down the process into its component parts. Make the dough on day one. The crust on day two and on the third day all that is left is the filling and baking the delicious, decadent quiche.

Mushroom Quiche | Mushroom Quiche with caramelized onions

How to make mushroom quiche?

Making a quiche is a longish process (and apparently, so is writing the blog). But it doesn’t ask for fancy techniques or equipment. With a little patience, you’ll have a 9-inch pie (or two 6-inch or seven 4-inch pies) that is one hundred percent worth the bake.

Get the dough ready

  • Start by cutting chilled, cubed pieces of butter into the flour using just your fingertips (this prevents the heat from the rest of the hand from melting the butter).
  • When you have a bread-crumb-like texture add ice-cold water one tablespoon at a time and bring the scraggy dough together.
  • You don’t have to knead it. Using only the heel of your hand push the dough away from you. Then bring it back with your fingertips till smooth.
  • A food processor completes the job faster, so if you have one (unlike me), use it. If the dough feels dry whisk in more chilled water. 
  • Shape the dough into a ball, flatten it slightly, cover in cling wrap and then refrigerate until it is firm and easy to handle. 

Quick note:

Keep your dough cold. It’s the golden rule for making a flaky crust. So, if the butter is melting when you’re cutting the flour, slide the whole thing in the refrigerator for 10 minutes. 

How long you need to chill the dough depends on the weather. If it’s hot, it can take up to 2 hours.

The refrigerated dough keeps for a week, so you can always prep ahead to save time. You can even freeze it for a month as long as you wrap it up tightly and properly.

Steps for baking pastry for making mushroom quiche

Rolling the quiche crust

  • On a very lightly floured surface (you don’t want excess dry flour), roll out the dough. 
  • Pick it up gently and place it in your pie dish. Push the dough inwards along the edges and the base with a very firm hand.
  • After you’ve made sure the dough fits the pan well, trim the dough that’s hanging over with a sharp knife and chill for another 20 minutes.

Blind baking the quiche crust

  • Prick the bottom of the chilled pie shell with a fork. The holes become windows that let steam escape, ensuring that your crust doesn’t puff like a balloon. 
  • Line the shell with parchment paper and weigh it down with baking beans, red kidney beans, or chickpeas.
  • Bake the crust for 15 to 20 minutes in a preheated oven. 
  • Remove the parchment paper along with the beans and then bake just the crust for another 5 minutes. 

Quick note:

The method of baking pie crusts is called blind-baking. Meaning you bake the pie before adding the actual filling. That’s how you get a perfectly cooked through, crispy and tender crust. If you directly bake the pie with the filling, the custard seeps into the bottom, making it dreadfully soggy. 

Ready pastry crust for Mushroom Quiche | Mushroom Quiche with caramelized onions

Prepare the mushroom quiche filling

  • Thinly slice two big onions and cook them in olive oil or butter on low heat along with a sprig of fresh thyme and some cumin powder.
  • When the onions are softened, about halfway through, add the balsamic vinegar. It leaves behind a layer of sweetness that you will love in the quiche. If you don’t have the vinegar, use brown sugar. 
  • Stir occasionally, sauté the onions till they are soft and brown. Add salt to taste right at the end. 

Quick note:

Caramelizing onions is optional. I know it takes time, but the explosion of taste they impart to the quiche is out of this world. I suggest doubling the amount, make them a few days ahead and store them in the fridge. Add them to any recipe when the mood strikes, not just mushroom quiche.

A quicker method to caramelizing onions is to splash a tiny amount of water and cover them. The buildup of steam cooks them through faster. It saves time. However, you would need to stir the onions every few minutes.

Caramelized onions on pastry base of mushroom quiche

Sautéing the mushrooms

  • Slice the mushrooms and sauté them in olive oil. Do it without salt, so they don’t seep water. 
  • Make sure you give the mushrooms enough room in the pan. Don’t overcrowd it, and you’ll come to appreciate how much buttery mushrooms can improve the flavor.

Making the custard

  • Mix eggs and cream with salt and pepper to taste. 
  • I added some more fresh thyme, although you can use any seasoning here.
Pouring the custard in the ready pastry for mushroom quiche

Baking the mushroom quiche

We’re finally in the home run of the quiche, where you layer and then bake. 

  • Spread the caramelized onions on the blind-baked crust. 
  • Follow it with a layer of sautéed mushrooms and some grated cheese. 
  • Pour the custard, and then sprinkle the top with more cheese.
  • As filler and pop of color, I included some diced green onions here and there. They are totally optional. 
  • The last touch is garnishing with four to five mushrooms.
  • Bake for 40 to 45 mins till the quiche puffs up and is colored golden. 
Filling the quiche for mushroom quiche recipe

Quiche ingredient substitutes

Flour: All-purpose flour, whole wheat flour, or half-and-half of both – all are a fabulous option. I’ve used them all in my quiche-making years when I was still running my bakery business and they used to sell like hotcakes. 

Mushrooms: Pick any; there are no hard and fast rules here. I used button mushrooms with a handful of baby portobellos.

Seasoning: The cumin in this recipe is optional. I like its smoky note, which acts as a natural counter to the sweetness of caramelized onions. In the custard, paprika, chili flakes, or any other fresh herb will do. 

Cheese:  Feel free to use whatever is convenient – Amul, Britannia, cheddar, gouda, or any other – as long as it is a hard cheese. The exception is feta. Mix it with regular cheese, and it works exquisitely in the recipe. 

I had a nice French Emmental cheese lying at home, and it melted beautifully, lending the quiche a rather creamy texture. 

Cream: Want to bring down the richness of quiche a bit? Switch to milk in the custard. 

Eggless: Some recipes use silken tofu instead of eggs in quiches. I’m yet to experiment but when I do, you’ll surely get a blog about it. 

Crust: The crust I used for the recipe is called pâte à foncer or flan pastry, a type of shortcrust pastry. Typically it uses an egg in the dough, but I left that out.

If you want to make a proper flan pastry, once the butter is cut into the flour, you’ll need to add an egg. Then use cold water to form the dough. The texture will be crisper, and you can store this pastry in the freezer for up to 3 months. 

Ready to serve Mushroom Quiche | Mushroom Quiche with caramelized onions

Serving the mushroom quiche

Allow the quiche rest to about twenty minutes after it’s baked. That’ll give the eggs time to cool and settle. Slice and then serve as a main dish or a side. We savored it with a bowl of fresh salad. The creamy mushroom quiche had a crust so flaky and custard so flavorful the entire pie was gone in no time at all!

A slice of Mushroom Quiche | Mushroom Quiche with caramelized onions
Mushroom Quiche | Mushroom Quiche with caramelized onions
Print Recipe
5 from 1 vote

Mushroom Quiche

Prep Time1 hr
Cook Time45 mins
Course: Main Course, Side Dish
Keyword: mushroom quuiche, mushroom quiche w/ caramelized onions, mushroom quiche recipe
Servings: 8 servings
Calories:
Author: Natasha Minocha

Ingredients

Pastry Crust

  • 250 gms All-purpose flour
  • 125 gms Butter, chilled, cut into small cubes I used salted butter. Add 1/2 tsp salt if using unsalted butter
  • 3-4 tbsp Water, ice cold

Mushroom Filling

  • 2 big Onions, thinly sliced
  • 1.5 tsp Cumin / Jeera powder
  • 2 tbsp Olive oil or butter
  • 1 tbsp Balsamic vinegar Or 1 tsp brown sugar
  • 1-2 sprigs Fresh thyme
  • Salt to taste
  • 300 gms Mushrooms, thinly sliced

Custard Filling

  • 4 Eggs
  • 125 gms Cream
  • 1 tsp Fresh thyme You can use dried thyme too.
  • Salt & pepper to taste
  • 150 gms Grated cheese
  • 1-2 tbsp Spring onion, only the green part, finely chopped Optional

Instructions

Pastry Crust

  • Start by cutting chilled, cubed pieces of butter into the flour using just your fingertips (this prevents the heat from the rest of the hand from melting the butter).
    You can also use a pastry cutter or two knives.
  • When you have a coarse bread-crumb-like texture add ice-cold water one tablespoon at a time and bring the dough together.
  • You don’t have to knead it. Using only the heel of your hand push the dough away from you. Then bring it back with your fingertips till smooth.
  • If the dough feels dry whisk in more chilled water. 
  • Shape the dough into a ball, flatten it slightly, cover in cling wrap and then refrigerate until it is firm and easy to handle. I refrigerated for about 15 minutes.

Blind Baking The Pastry Crust

  • Preheat your oven to 180C. Keep a 9" pie dish handy.
  • On a very lightly floured surface (you don’t want excess dry flour), roll out the dough to an approximately 12" circle. 
  • Pick it up gently and place it in your pie dish. Push the dough inwards along the edges and the base with a very firm hand.
    You can also wrap the dough around your rolling pin and then transfer it to your pie dish.
  • After you’ve made sure the dough fits the pan well, trim the dough that’s hanging over with a sharp knife and chill for another 20 minutes.
  • Prick the bottom of the chilled pie shell with a fork.  
  • Line the shell with parchment paper and weigh it down with baking beans, dry red kidney beans, or chickpeas.
  • Bake the crust for 20 minutes in a preheated oven at 180C. 
  • Remove the parchment paper and the beans and return the pie to the oven for another 10 minutes.

Mushroom Quiche Filling

  • While the crust is baking, prepare the filling.
  • Thinly slice the onions and cook them in 1 tbsp olive oil or butter on low heat along with a sprig of fresh thyme and cumin powder. 
  • When the onions are softened, about halfway through, add the balsamic vinegar. If you don’t have the vinegar, use brown sugar. 
  • Stir occasionally, and sauté the onions till they are soft and brown. Add salt to taste right at the end. Transfer to a bowl and keep aside.
  • Add a tbsp of olive oil and sauté the mushrooms in the same pan, until they are softened and cooked.
  • In a separate bowl, whisk together the eggs, cream, fresh / dried thyme, salt, and pepper.
    You can use any seasoning you prefer.

Assembly

  • Spread the caramelized onions on the pie crust.
  • Top this with the sauteed mushrooms ( save 5-6 for the top)and some green onion.
  • Sprinkle the grated cheese and pour over the egg cream mixture. Top with more grated cheese and the remaining mushrooms.
  • Bake this at 180C for 40-45 minutes until the center is set and the quiche, golden.
  • Let it rest for a few minutes before slicing and serving. Enjoy!
Mushroom Quiche | Mushroom Quiche with caramelized onions