Step 1

In a medium saucepan, cover the potatoes and carrots with water. Boil for 7-10 minutes, or until tender (but not falling apart). Drain and set aside.

Step 2

Heat the olive oil in a large skillet over medium-high heat. Add the onions, celery, and salt. Cook, stirring regularly until the onions have started to brown and caramelize. I like to go pretty far at this stage for added flavor. Stir in the mushrooms, garlic, and thyme and cook for another 2-3 minutes. Reduce the heat to medium, sprinkle the mixture with the flour and use a whisk to mix it in. Cook for a minute allowing the flour to toast a bit. Combine the broth and heavy cream together and whisk it into the mushroom mixture 1/2 cup at a time. Really go at it with the whisk. Allow the mixture to simmer, stirring frequently, until it thickens (a spatula run through the skillet should leave a trail), 8-10 minutes. Remove from heat and stir in the frozen peas, the cooked potatoes and carrots, half of the chives, and half the lemon zest. Allow to cool completely.

Step 3

When you’re ready to bake your pot pie, heat the oven to 425°F / 220°C with a rack in the center. A good rule of thumb is to heat the oven for at least 30 minutes before baking pies - you want to make sure it’s hot and ready to go. Also, clear a space in the freezer to chill the pie before baking.

Step 4

If your pie dough has been chilling overnight allow it to sit at room temperature for a bit before rolling out - 15 minutes or so. Butter your 9 (or 10-inch) pie dish and sprinkle with the remaining lemon zest. Lightly flour your work surface and rolling pin. Roll the pie dough out, large enough to relax into your pie dish with extra dough extending a bit beyond the edge. As you’re rolling the dough, you’re going to want to turn the pie dough clockwise after every few passes with the rolling pin to prevent sticking. Flour more as needed.

Step 5

Transfer the dough for the bottom crust into the pie dish by gently wrapping it around your rolling pin and unrolling it across your pie dish. Coax the bottom pie dough into place, and then press into the pan to anchor it. Trim any excess dough if needed with scissors. Roll out the top pie crust. You want to work relatively quickly so your dough doesn’t warm.

Step 6

Gently pile the cooled pot pie filling into the dough-line pie dish. Drape the other (top) round of pie dough on top and trim so you have about 1-inch of dough hanging beyond the edge of the dish. Press the edges of the pie shell together to seal things, and fold the edge of the crust over or under, and crimp or pinch around the edge using a fork or pressing your thumb and forefinger of one hand into the forefinger of the other hand. Carefully place the entire pie in the freezer for 15 minutes.

Step 7

When it is time, remove the pie from the freezer, cut a few slits in the top to allow steam to escape while the pie bakes, and gently brush with enough heavy cream to coat all of the top crust.

Step 8

Put the pie on a baking sheet to catch any drips and place in the oven. Dial back the heat to 375°F / 190°C. You’re going to bake the pie for about an hour, but start checking on it about 45 minutes in. At this point I often spin it 180 degrees in the oven, and make note if the top of the pie is getting too dark. If so, place a sheet of aluminum foil (or pie shield) over it until the bottom catches up. When everything is deeply golden remove the pie from the oven and allow to cool a bit before slicing. If you have leftovers, you can refrigerate this pie for up to a week.