- 1 1/2 lbs boneless skinless chicken breasts and/or thighs, trimmed
- 3 cups chicken broth
- 2 tbsp vegetable oil
- 1 onion, chopped fine
- 3 carrots, peeled and sliced 1/4 inch thick
- 2 small celery ribs, minced
- salt and pepper
- 10 ounces cremona mushrooms, trimmed and sliced thin
- 1 teaspoon soy sauce
- 1 teaspoon tomato paste
- 4 tbsp unsalted butter
- 1/2 cup all-purpose flour
- 1 cup whole milk
- 2 teaspoons lemon juice
- 3 tbsp minced fresh parsley
- 3/4 cup frozen peas
- 2 cups (10 oz) all-purpose flour
- 2 teaspoons baking powder
- 3/4 teaspoon salt
- 1/2 teaspoon pepper
- 1/8 teaspoon cayenne pepper
- 6 tbsp unsalted butter, cut into 1/2 inch pieces and chilled
- 1 oz Parmesan cheese, grated fine
- 3/4 cup plus 2 tbsp heavy cream
- FOR THE FILLING: Bring chicken and broth to simmer in covered Dutch oven and cook until chicken is tender and cooked through, 8 to 10 minutes. Transfer chicken to large bowl. Pour brother through fine-mesh strainer into liquid measuring cup and reserve. Meanwhile, adjust oven rack to upper-middle position and heat oven to 450 degrees.
- FOR THE TOPPING: Combine flour, baking powder, salt, pepper, and cayenne in large bowl. Sprinkle butter pieces over top of flour. Using fingers, rub butter into flour mixture until it resembles coarse cornmeal. Stir in Parmesan. Add cream and stir until just combined. Crumble mixture into irregularly shaped pieces ranging from 1/2 to 3/4 inch each onto parchment paper-lined rimmed baking sheet. Bake until fragrant and starting to brown, 10 to 13 minutes. Set aside.
- Heat 1 tablespoon oil in now-empty pot over medium heat until shimmering. Add onion, carrots, celery, 1/4 teaspoon salt, and 1/4 teaspoon pepper; cover and cook, stirring occasionally, until just tender, 5 to 7 minutes. While vegetables are cooking, use 2 forks to shred chicken into bite-size pieces. Transfer vegetables to bowl with chicken; set aside.
- Heat remaining 1 tablespoon oil in again-empty pot over medium heat until shimmering. Add mushrooms; cover and cook, stirring occasionally, until mushrooms have released their liquid, about 5 minutes. Remove cover and stir in soy sauce and tomato paste. Increase heat to medium-high and cook, stirring often, until liquid has evaporated, mushrooms are well browned, and dark fond begins to form on surface of pan, about 5 minutes. Transfer mushrooms to bowl with chicken and vegetables. Set aside.
- Melt butter in again-empty pot over medium heat. Add flour and cook, stirring constantly, for 1 minute. Slowly whisk in reserved broth and milk. Bring to simmer, scraping up any browned bits, and cook until sauce thickens, about 1 minute. Off heat, stir in lemon juice and 2 tablespoons parsley, then stir chicken mixture and peas into sauce. Season with salt and pepper to taste.
- Pour chicken mixture into 13 by 9-inch baking dish. Scatter crumble topping evenly over filling. Place pot pie on aluminum foil-lined rimmed baking sheet and bake until filling is bubbling and topping is well browned, 12 to 15 minutes. Sprinkle with remaining 1 tablespoon parsley and serve.