Add the flour, powdered sugar, and salt to the bowl of a food processor, and pulse until well combined. Add in the butter and pulse 5-7 times, or until the butter is broken down into tiny pebbles.

With the motor running, add in the egg and let the dough process until it forms together into a cohesive ball around the blade, about 1 minute.

Transfer the dough to a work surface dusted with flour.

Roll out the pie dough to an 11″ circle and line a 9” pie plate, crimp the edges as desired.

Transfer the dough to the freezer to chill while you preheat the oven.

Preheat the oven to 375 and place a rack on the lower and a rack in the middle part of the oven.

Line the pie dough with a parchment round piece of paper and then add pie weights (or dry rice or beans or lentils), making sure to push pie weights to the edges. Bake for 25 minutes on the lower rack, then remove the parchment and pie weights and bake for an additional 5 minutes, or until the bottom of the pie crust looks dry. Set aside until ready to use.

Lower the heat to 325º.

Whisk together the sugar, salt, eggs and yolks. Add in the milk, cream and vanilla and whisk to combine.

Strain the mixture twice through a fine-mesh strainer, removing any coagulated bits of egg.

Carefully pour the filling into the baked pie shell. Grate about ½ teaspoon nutmeg over the top of the pie.

Bake on the middle rack for 40-45 minutes, or until the custard has set nearly all the way through, with a slight wobble in the middle. The pie should have a temperature of 180ºF.

Remove the pie from the oven, and place it on a rack to cool. When it's completely cool, refrigerate until you're ready to serve.

The pie can be baked up to 1 day ahead of time.