For the filling:
1½ pounds boneless, skinless chicken thighs and/or breasts
3 cups low-sodium chicken broth
2 tablespoons vegetable oil
1 onion, finely chopped
3 carrots, peeled and sliced ¼-inch thick
2 small celery ribs, minced
Salt and freshly ground pepper
10 ounces cremini mushrooms, thinly sliced
1 teaspoon soy sauce
1 teaspoon tomato paste
4 tablespoons unsalted butter
½ cup all-purpose flour
1 cup whole milk
2 teaspoons lemon juice
¾ cup frozen peas
For the topping:
2 cups all-purpose flour
2 teaspoons baking powder
¾ teaspoon salt
½ teaspoon pepper
⅛ teaspoon cayenne pepper
6 tablespoons unsalted butter, cut into ½-inch pieces and chilled
½ cup (1 ounce) grated Parmesan cheese
¾ cup plus 2 tablespoons heavy cream
The recipe calls for a 9 x 13-inch baking dish, but I successfully made it in two smaller dishes (one to keep and one to give). You can also turn this into a make ahead meal by by making the filling and refrigerating it in the baking dish. If making the topping a day early, as well, store it in an airtight container. Bake the chilled filling for about 30-35 minutes, then top it with the biscuit crumble and continue baking until the filling is heated through and the crumble is lightly browned, about 15 additional minutes.
To make the filling, bring chicken and broth to a simmer in a covered Dutch oven. Cook for 8-10 minutes, until the chicken is tender and cooked through. Use tongs to remove chicken to a large bowl and set aside. Pour broth through a fine mesh strainer into a liquid measuring cup and reserve. Place oven rack in the upper-middle position and heat the oven to 450º.
Prepare the topping by combing the dry ingredients in a large bowl. Using your fingers, work in the butter pieces until a coarse texture is achieved. Stir in the Parmesan, then stir in the cream until just combined. The dough will be shaggy. Crumble the dough into irregularly shaped ½ to ¾-inch pieces onto a parchment-lined rimmed baking sheet. Bake until fragrant and starting to brown, 10-13 minutes.
Meanwhile, heat 1 tablespoon of oil in the Dutch oven over medium heat until shimmering. Add the onion, carrots, celery, ¼ teaspoon salt and ¼ teaspoon pepper. Cover and cook, stirring occasionally, until just tender, 5-7 minutes. While vegetables are cooking, shred the chicken into bite-size using two forks. Add vegetables to bowl with shredded chicken and set aside.
Heat the remaining tablespoon oil in the Dutch oven set over medium heat until shimmering. Add mushrooms. Cover and cook, stirring occasionally, until the mushrooms have released their liquid, about 5 minutes. Stir in soy sauce and tomato paste. Increase heat to medium high, stirring frequently, until the liquid has evaporated, mushrooms are well browned and brown bits begin to form on the sides of the pan, about 5 minutes. Transfer mushrooms to bowl with chicken and vegetables. Set aside.
Melt butter in the Dutch oven set over medium heat. Once melted, add the flour and cook, stirring constantly, for 1 minute. Gradually whisk in the reserved chicken broth and milk. Bring to a simmer, scraping up any browned bits, and cook until the sauce thickens, about 1 minute. Remove from heat and stir in lemon juice and parsley. Add the chicken mixture and peas to the pan and stir to combine. Adjust for seasoning as needed.
Pour the chicken into a 9 by 13-inch baking dish. Scatter the crumble topping over evenly over the filling. Place the pot pie onto a foil-lined rimmed baking sheet and bake until filling is bubbling and top is well browned (mine wasn’t quite as browned as it should’ve been, but we were hungry!), about 12-15 minutes. Sprinkle with remaining parsley and serve immediately.