Cooking Steps
In a large food processor, 360 g. all-purpose flour, 1 tsp. baking powder, and 1 tsp. kosher salt until combined.
Add 1 c. unsalted butter and pulse until pea-sized and some slightly larger pieces form.
With the processor running, slowly pour in 1/2 cup ice water, 1 tablespoon at a time, until the dough is smooth and moist.
Turn out dough onto a lightly floured surface.
Form into 2 balls, then flatten into 2 discs. Cover with plastic wrap and refrigerate at least 30 minutes or up to 3 days.
For the filling, melt the butter in a large saucepan over medium heat.
Add finely chopped yellow onions and finely chopped carrots and cook, stirring occasionally, until vegetables are beginning to soften (about 10 minutes).
Stir in finely chopped garlic, then stir in 1/2 c. all-purpose flour and cook, stirring constantly, until mixture turns golden and is beginning to bubble (about 3 minutes).
Gradually whisk in chicken broth. Bring to a boil and cook, stirring occasionally, until thickened (about 5 minutes).
Remove from heat and stir in heavy cream, then add poached skinless chicken breasts, cut into cubes, frozen peas peas, chopped fresh parsley, and chopped fresh thyme leaves.
Season with kosher salt and freshly ground black pepper. Let cool.
Preheat oven to 375°. Place a rack in center of oven.
On a lightly floured surface, roll out one disc of dough to a large round about 1/4″ thick.
Transfer to a deep 9″ pie dish, then add filling.
Roll out second disc of dough to a large round about 1/4″ thick. Arrange on top of filling.
Press edges of top and bottom dough rounds together.
Using a sharp knife or kitchen shears, trim edges of dough, leaving about 1/4″ overhang.
Fold excess dough underneath dough on top rim of pie pan. Using clean fingers, crimp to seal.
Brush top of dough with egg wash.
Bake pot pie until crust is golden brown, about 45 minutes.
Let cool at least 15 minutes before serving.
Video