Step 1

Make the pastry dough. Combine 6 oz (1 ¼ cups) AP flour, ½ tsp sugar, ¼ tsp Kosher salt, and 1 stick cubed butter into the bowl of a food processor fitted with blade attachment. Pulse several times, until the butter is coarsely mixed into the flour.

Step 2

Pulse with ice water. Add ¼ cup ice water to the bowl, then pulse until the dough forms. It should be moist and clump together around the blade. If you squeeze it together with your hands, it will easily become uniform.

Step 3

Shape, then chill. Dump the dough out onto a large piece of plastic wrap, then flatten and wrap, pressing the dough into a disk. Refrigerate for 2 hours.

Step 4

Roll out the dough. Roll the dough out on a lightly floured surface to a 12" round circle that is ~¼" thick.

Step 5

Transfer to the tart pan. Grease a 9" round tart pan with baking spray, then carefully lift and transfer the rolled out dough onto the pan. Use your hands to gently press the dough along the bottom and up the sides of the pan, so it fits snuggly. Allow excess dough to hang over the sides, then use a paring knife to gently cut away any excess. The dough should be flush with the sides of the pan.

Step 6

Freeze the dough (second chill). Use a fork to prick the bottom of the tart dough all over, then freeze for 1 hour. Do NOT skip this step!

Step 7

Partially bake the dough. When ready, preheat an oven to 400F. Cover the chilled tart dough tightly with aluminum foil, pressing the foil into the pressed dough. Bake for 20 minutes. Carefully remove the foil, then bake for an additional 3-5 minutes, or until the dough is a light golden brown.

Step 8

Make the filling. Melt 1 Tbsp unsalted butter in a large skillet over medium-high heat. Add sliced shallots, then sauté for 3-5 minutes, stirring occasionally. Add 8 oz fresh baby spinach, 1 tsp Kosher salt, and ½ tsp black pepper. Cook stirring often, about 5 minutes, until the spinach has cooked down completely.

Step 9

Assemble the quiche. Place the quiche pan on a foil-lined rimmed baking sheet in case excess filling overflows. Spread the filling into the partially baked tart dough into an even layer. Sprinkle ¾ cup grated Gruyere cheese on top. In a small bowl, whisk together ¾ cup heavy cream and 2 eggs. Carefully pour the mixture on top of the filling. It should go all the way to the top.

Step 10

Bake the quiche. Carefully transfer the sheet pan into the preheated 400F oven. Bake for 35-40 minutes, or until the top has puffed up slightly and is a deep golden brown. Allow quiche florentine to cool for at least 5-10 minutes before slicing. Serve immediately.