Step 1

Preheat the oven to 425 degrees F. Line a sheet pan with parchment paper

Step 2

In a large skillet over medium heat, combine 3 tbsp of olive oil, the leeks, salt, pepper, and red pepper flakes. Cook, stirring occasionally, until the leeks are soft, about 4 minutes.

Step 3

Push the leeks to the perimeter of the pan, then add the remaining 1 tbsp olive oil and the mushrooms. Cook until the mushrooms have given off their juices and then shriveled, about 10 minutes, leaving the leeks on the perimeter.

Step 4

Stir in the thyme and peas and cook another minute, folding in the leeks.

Step 5

Place the pie dough on the prepared sheet pan and sprinkle the nutritional yeast all over it, pressing the flakes into the dough with your fingers or a rolling pin

Step 6

Spoon the mushroom-leek filling into the center, spreading it in an even layer and leaving a 1-inch border, then folding the edges over the filling, overlapping aa sou work your way around the perimeter.

Step 7

Brush the dough with the whisked egg and sprinkle with the sea salt.

Step 8

Bake in the heated oven until the crust is golden, 20 to 25 minutes,