Step 1

To make the crust, in a medium bowl, whisk together flour, sugar, and salt. Add cold, cubed butter and, using your fingers, work the butter into the flour mixture. Quickly break the butter down into the flour mixture, some butter pieces will be the size of oat flakes, some will be the size of peas.

Step 2

Create a well in the butter and flour mixture and pour in the cold buttermilk. Use a fork to bring to dough together. Try to moisten all of the flour bits. On a lightly floured work surface, dump out the dough mixture. It will be moist and shaggy. That’s perfect. Wrap disk in plastic wrap and refrigerate for 1 hour while you make the filling.

Step 3

To roll out the dough, remove one of the pie dough disks from the fridge. On a lightly floured surface, roll dough out into about a 13-inch round. Roll the dough a few strokes, then use your fingers to move the emerging circle around the floured surface. This ensures that the dough isn’t sticking to the work surface. The circle won’t be perfect, that’s ok.

Step 4

Try not to get any rips in the rolled out dough, but if you do, they can be patched together with extra dough. When you roll the dough and you can see it start springing back, that means that the butter is warming and the crust shouldn’t be rolled out anymore. Gently lift the 13-inch round from the floured surface and center in a deep 9-inch round pie dish. Trim the overhang to be about 1-inch over the edge of the pie pan and fold the overhang under into the pie dish. Crimp the edges as you’d like pinching with your fingers or pressing with the tines of a fork.

Step 5

To make the filling, start by cooking the sausage, followed by all of the vegetables.

Step 6

Place 1 tablespoon of oil in a medium skillet over medium heat. Add the sausage and cook, breaking up with a spoon or spatula as it browns. Increase the temperature to high to really crisp the beat. Cook through, about 5 minutes, then remove just the sausage and place in a medium bowl.

Step 7

With the oil remaining in the pan, add the onions and garlic. Cook until just translucent, about 3 minutes, then add the bell pepper. Cook until the pepper has softened and much of the water has cooked out, about 5 minutes. When softened and browned spoon the onion and bell pepper mixture atop the cooked sausage and set aside.

Step 8

Add the remaining 2 tablespoons of oil to the pan, place over medium heat and add the sliced mushrooms. Toss to move the move the mushrooms around the pan and coat in oil then allow to cook undisturbed for 2 minutes. Sprinkle with salt and pepper. Cook, stirring occasionally until water has been released from the mushrooms and they begin to brown. Continue to brown on all sides, cooking the mushrooms thoroughly, about 6 to 8 minutes. Once browned well, spoon the mushrooms atop the sausage, onion, and pepper mixture.

Step 9

In a medium bowl whisk the six eggs until well combined.

Step 10

Whisk in the milk and cream. Whisk in the spices, salt and pepper. Not it’s time to assemble!

Step 11

Place a rack in the center of the oven and preheat oven to 375 degrees F. Place a rimmed baking sheet in the oven to heat as the oven preheats.

Step 12

Sprinkle the prepared pie crust with half of the cheese. Top with the sausage and mushroom mixture. Sprinkle with the thickly sliced pepperoni and the black olives. Pour over the egg custard mixture and sprinkle with the remainder of the cheese.

Step 13

Place quiche on the heated baking sheet and bake until cooked through and lightly puffed, about 40 to 45 minutes.

Step 14

Remove from the oven and turn the oven to broil.

Step 15

Spread pizza sauce over the center of the cooked quiche. Top with pepperoni if using. Top with cheese. Place under the broiler until the cheese is melted and bubbly. Keep an eye on the quiche so it doesn’t brown too much.

Step 16

Remove from the oven. Allow to cool for about 30 minutes before slicing and serving slightly warm. To store, wrap in plastic wrap and refrigerate. Quiche will last chilled for up to 4 days.