Instructions

• Make the shortcrust: In a food processor, combine 2 ¼ cups all-purpose flour, 12 tablespoons ice cold butter (cut into cubes), and ½ teaspoon salt. Pulse until the mixture resembles coarse crumbs.
• Add 5 tablespoons ice cold water to the processor and pulse just until the dough begins to come together and can be formed into a ball.
• Turn the dough onto a piece of plastic wrap, flatten it into a disk, wrap tightly, and refrigerate for at least 30 minutes (60 minutes is better).
• Preheat the oven to 375°F. Lightly flour a work surface and place the chilled dough disk on it. Using a rolling pin, press and roll the dough into a roughly 14-inch circle.
• Transfer the rolled dough into a 9-inch springform pan: lift it carefully (do not stretch), fit it into the pan, and gently press it into the bottom and up the sides, tucking it into the creases. Trim the edge now or leave an overhang to trim after baking, according to your preference.
• Line the crust with a piece of parchment paper or foil and fill to the top with ceramic pie weights, dried beans, or dried rice. Fold any excess paper or foil over the crust edges and bake the crust at 375°F for 45 minutes.
• While the crust bakes, prepare the filling: In a large bowl, whisk 15 large eggs and 2 ¾ cups half & half until smooth. Whisk in 2 teaspoons Italian seasoning, 1 teaspoon salt, ¾ teaspoon onion powder, ¾ teaspoon garlic powder, and ½ teaspoon cracked black pepper.
• Fold the filling additions into the egg mixture: 2 ½ cups shredded fontina cheese (or white cheddar), 8 ounces frozen chopped spinach (thawed and squeezed very well, about ½ cup), ½ cup chopped sun-dried tomatoes, and ½ cup chopped feta cheese (or sliced green olives). Mix until evenly combined.
• When the crust’s par-bake is finished, use the edges of the parchment or foil to lift out the weights and remove the paper/foil. If the crust edge is browning, tent the exposed edge with strips of foil to prevent further browning. Carefully pour the filling into the par-baked crust.
• Return the filled quiche to the oven and bake at 375°F for 110–130 minutes, or until an instant-read thermometer inserted into the deepest part of the quiche reads 160°F.
• Remove the quiche from the oven and let it cool at room temperature for at least 2 hours. If you left an overhang, trim the edges now. Release the quiche from the springform pan.
• Slice and serve at room temperature, or reheat individual slices before serving.