Step 1

Grease a pie pan with 1 tablespoon of butter. If you're using store-bought dough, place the bottom crust in the pie pan. If you made 3-Ingredient Pie Crust, cut 1/3 of the dough off to be used as the top crust, wrap it in plastic, and refrigerate until you're ready to use it later.

Step 2

Dust your work surface with flour and roll out the bigger 2/3 piece of dough into a circle that is 16 inches in diameter and about 1/4 inch thick. Line the pie pan with it.

Step 3

Beat the egg white until frothy, then brush the bottom crust with it. Let the crust rest in the fridge.

Step 4

Place a rack in the center of your oven along with a sheet pan and preheat it to 350ºF. Place a deep skillet over medium heat and add 5 tablespoons of salted butter to the pan. Once the butter foams, swish it around the pan until it turns an amber color and smells of hazelnuts.

Step 5

Add the diced onions to the brown butter. Cook until the onions are translucent, about 5 minutes. Add the garlic, and cook for one minute. Sprinkle the flour over the onions and garlic in the skillet and continue to cook and stir for two minutes more.

Step 6

To the pan, add veggie broth, milk, and salt. Whisk to combine and dissolve any flour off the bottom of the skillet. Then add the bay leaf, rosemary, thyme, sage, pepper, and soy sauce. Whisk occasionally as the liquid simmers and thickens.

Step 7

Add the pint of diced mushrooms and the diced potato to the pan. Stir to combine and cook until the gravy has thickened more and reduced some, about 5 minutes.

Step 8

Remove the skillet from the heat. Finally, add the frozen mixed vegetables and allow them to cool the ingredients in the pan.

Step 9

Take the pie pan out of the fridge, prick the bottom crust a few times with a fork, and add the cooled filling to the pie pan. Dice the last tablespoon of butter and sprinkle it over the filling.

Step 10

Roll the smaller piece of dough into a circle, about 10 inches wide and 1/4 inch thick. Cover the pie with it.

Step 11

Beat the egg yolk. Trace a bit of yolk along the top edge of the bottom and top crusts. Fold the bottom crust over the top crust and crimp the edges shut. Cut vents into your top crust. Brush egg yolk in a light layer over the top crust.

Step 12

Bake for 45 to 50 minutes, or until the pie dough is golden and flaky. Allow the Veggie Pot Pie to cool for ten minutes before serving.