Ingredients

Pastry Crust

• 1 cup all-purpose flour (127 grams)
• 1⁄2 cup salted butter (113grams), chilled, cut into small cubes.
• 3-4 Tbsp. water, ice cold

Mushroom Filling

• 2 large onions, thinly sliced
• 1 1⁄2 tsp. cumin powder
• 2 Tbsp. olive oil or butter
• 1 Tbsp. balsamic vinegar
• 1-2 sprigs fresh thyme
• Salt to taste
• 10 oz. cremini mushrooms, thinly sliced

Custard Filling

• 4 eggs
• 1⁄2 cup heavy cream
• 1 tsp. fresh/dried thyme
• Salt and pepper to taste
• 6 oz. grated Gruyere OR Fontina cheese OR a mix of both, divided
• 1-2 Tbsp. scallion, only the green part, finely chopped (save the whites for your side salad)

Instructions

Pastry Crust

1. 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.
2. When you have a coarse bread-crumb-like texture add ice-cold water one tablespoon at a time and bring the dough together.
3. 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.
4. If the dough feels dry add in more chilled water. 
5. Shape the dough into a ball, flatten it slightly, cover in cling wrap and then refrigerate until it is firm and easy to handle, about 15 minutes.

Blind Baking The Pastry Crust

1. Preheat your oven to 375°. Keep a 9″ pie dish handy.
2. On a very lightly floured surface (you don’t want excess dry flour), roll out the dough to an approximately 12″ circle. 
3. 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.
4. 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.
   The Hubs used the extra dough and added it around the perimeter and notched it with the end of a knife to crimp the edges. This helps the crust from shrinking.
5. Prick the bottom of the chilled pie shell with a fork.  
6. Line the shell with parchment paper and weigh it down with baking beans, dry red kidney beans, or chickpeas.
7. Bake the crust for 15-16 minutes in the preheated oven. 
8. Remove the parchment paper and the beans and return the pie to the oven for another 7-8 minutes. Remove from oven and cool on a rack for 15 minutes.

Mushroom Quiche Filling

1. While the crust is baking, prepare the filling.
2. Thinly slice the onions and cook them in 1 tablespoon olive oil or butter on low heat along with a sprig of fresh thyme and cumin powder. 
3. As the onions are softening, after 5 minutes, add the balsamic vinegar.
4. Stir occasionally, and sauté the onions until they are soft and brown, 8-10 minutes total. Add salt to taste right at the end. Discard thyme sprigs and transfer to a bowl and keep aside.
5. Add a tablespoon of olive oil and sauté the mushrooms in the same pan, until they are softened and cooked, about 8 minutes.
6. In a separate bowl, whisk together the eggs, cream, fresh/dried thyme, salt, and pepper. You can use any seasoning you prefer.

Assembly

1. Spread the caramelized onions on the pie crust.
2. Top this with most of the sautéed mushrooms (save 8-10 for the top) and some green onion.
3. Sprinkle 2/3 of the grated cheese and pour over the egg cream mixture. Top with remaining 1/3 grated cheese and the remaining mushrooms.
4. Bake this at 350° for 40-45 minutes until the center is set and the quiche, golden.
5. Let it rest for about 15 minutes before slicing and serving.

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