Chicken Pot Pie with Buttermilk Biscuit Topping

Ingredients

• For the chicken:
• 2 quarts homemade or store-bought low-sodium chicken stock
• 4 1/2 pounds assorted bone-in, skin-on chicken legs, thighs, and breasts
• 1 large onion, diced
• 2 large carrots, diced
• 2 large celery ribs, diced
• 2 medium garlic cloves, crushed
• 2 sprigs thyme
• 1 sprig flat-leaf parsley
• 1 sprig rosemary
• 1 bay leaf
• For the filling:
• 1/2 ounce gelatin
• 1/4 cup reserved chicken stock, cooled
• 4 ounces unsalted butter
• 4 ounces all-purpose flour
• 1 medium onion, diced
• 1 large carrot, diced
• 1 large celery rib, diced
• 1/2 cup dry white wine
• 1 quart reserved chicken stock
• 5 ounces frozen peas
• 3 ounces drained and diced pimento peppers, or more to taste
• 1 3/4 teaspoons Diamond Crystal kosher salt; for table salt, use about half as much by volume or the same weight
• 1/4 ounce fresh thyme leaves
• 1 teaspoon freshly ground black pepper, or more to taste
• 1 1/2 teaspoons Worcestershire sauce
• 28 ounces poached chicken, from above, or more to taste
• For the biscuit topping:
• 9 ounces all-purpose flour, such as Gold Medal
• 1 ounce sugar
• 1 tablespoon baking powder
• 1 1/2 teaspoons Diamond Crystal kosher salt; for table salt, use about half as much by volume or the same weight
• 8 ounces cold unsalted butter, cut into 1/2-inch cubes
• 8 ounces cultured lowfat buttermilk or kefir, straight from the fridge

Directions

1. For the Chicken: Add the chicken stock, chicken pieces, onion, carrots, celery, garlic, thyme, parsley, rosemary, and bay leaf to a 5-quart stainless steel pot or saucier. Cover the pot and warm it over medium-high heat until a digital thermometer reads about 150 degrees F (66 degrees C). Regulate the heat to keep it within plus or minus 10 degrees F, then cook until the thickest section of the chicken reaches 135 degrees F (57 degrees C), about 1 hour. Use tongs to transfer the chicken to a rimmed platter, and tent it loosely. Pour the stock through a mesh sieve into a large bowl, discard the strained solids, and leave the stock to cool.
2. For the Filling: In a small bowl, whisk the gelatin with 1/4 cup (55ml) cooled stock until smooth and lump-free, then set it aside. Melt the butter in a 5-quart saucier over medium-low heat, and whisk in the flour. Cook the roux with a heatproof spatula, stirring until it smells toasty and turns a pale nutty blond, about 5 minutes; if it is moving too slowly, adjust the heat a bit. Add the diced onion, carrots, and celery, and cook, stirring, until the vegetables have softened slightly, about 7 minutes more.
3. Pour in the white wine and 1 quart reserved stock, stirring the whole time so the sauce stays smooth; any extra poaching stock can be saved for another use. Raise the heat to medium-high and bring the mixture to a boil while continuing to stir. As soon as it bubbles, take it off the heat. Mix in the frozen peas, diced pimentos, and bloomed gelatin, then add the salt, thyme, pepper, and Worcestershire sauce. Stir until the gelatin disappears into the sauce, then season to taste.
4. Remove and discard the chicken skin and bones, then shred or dice the meat and fold it into the filling. If it works better for your timing, cover and refrigerate the filling up to 3 days, or freeze it in an airtight container for 3 months. If baking now, spoon the filling into 6 individual oven-safe dishes, or into a 2-quart glass or ceramic baking dish, approximately 7 by 11 inches. Set the dish or dishes on a foil- or parchment-lined baking sheet and keep nearby.
5. For the Biscuit Topping: Move an oven rack to the middle position and heat the oven to 400 degrees F (200 degrees C). Whisk the flour, sugar, baking powder, and salt together in a medium bowl. Add the butter, toss to separate the cubes, and press each piece flat with your fingertips. Keep rubbing and flattening until the butter is in small, cereal-flake-like bits. Use a flexible spatula to stir in the buttermilk, then scatter the thick dough over the filling in 1-tablespoon portions.
6. Bake until the biscuits are deeply golden and the filling is hot and bubbling, about 45 minutes to 1 hour, depending on whether the filling was cold. Rest for at least 30 minutes before serving so the filling can thicken and cool to a comfortable temperature. Cover leftovers with foil, refrigerate up to 3 days, and reheat before serving.