SINGLE CRUST INGREDIENTS
3 cups unbleached all-purpose flour
1 1/2 tsp kosher salt
1 tsp baking powder
1/2 cup cold solid vegetable shortening, cut into small cubes
1/4 cup cold unsalted butter, cut into small cubes
1/2 to 2/3 cup ice water
PIE FILLING INGREDIENTS (SINGLE BATCH or DOUBLE BATCH)
Skinless, boneless chicken thighs (2 lb or 4 lb)
Olive oil (3 Tbsp or 6 Tbsp)
Chicken stock (5 cups or 10 cups)
Unsalted butter (3/4 cup or 1 1/2 cups)
Yellow onions, chopped (2 or 4)
Carrots, peeled and cut into 1/2-inch dice (2 or 4)
Celery ribs, cut into 1/2-inch dice (2 or 4)
Unbleached all-purpose flour (3/4 cup or 1 1/2 cups)
Heavy cream (1/4 cup or 1/2 cup)
10-oz package(s) frozen peas, thawed (1 or 2)
Pearl onions, (1-1/2 cups or 3 cups); see Ingredient Notes below
Finely chopped fresh flat-leaf parsley (1/2 cup or 1 cup)
Egg Glaze, 1 large egg and 1 Tbsp water (for either single or double batch)
Kosher salt and freshly ground black pepper
One or two 9-by-13-inch baking dishes; one or two half sheet pans for roasting the chicken and for placing under the pie(s) in the oven.
BIG BATCH NOTES
If making two pies, make two single batches of dough, as a double batch will overwhelm a standard-size food processor. The filling can be made in a large Dutch oven, or it can be made in two large saucepans and then combined before dividing it between the baking dishes. A double batch of the filling and crust makes enough for two 9-by-13-inch baking dishes or three 9- or 10-inch deep-dish pie dishes.
If you wish, buy rotisserie chicken instead of cooking the chicken thighs. You’ll need 4 cups chicken for the small batch and 8 cups chicken for the double batch.
For a really big gathering, follow the island’s lead and ask others to bring their version of this recipe. A citrusy salad with bitter greens and toasted nuts is a good accompaniment. For dessert, offer ice cream and fresh fruit.
Fresh pearl onions come in white, yellow, and red varieties, sometimes packaged together in a combination of all three colors. To peel them, drop them into a saucepan of boiling water over high heat and cook until the skins loosen, about 1 minute. Drain in a colander and rinse under cool running water until cold. Using a small, sharp knife, trim off a thin slice from the top and bottom of each onion, then make a shallow vertical incision in the skin and peel them. To skip the peeling altogether, use thawed frozen pearl onions.
Since a food processor will only fit one batch of dough, you’ll have to make one batch per pie.
Make the pastry
For each pie, in a food processor, combine the flour, salt, and baking powder and pulse a few times until mixed. Scatter the shortening and butter over the flour mixture and mix quickly and lightly with your fingers until each piece is coated with flour. Pulse 10 times, until the fat is the size of peas. With the motor running, add just enough of the ice water to moisten the flour mixture and for the dough to come together in clumps.
Lightly flour a work surface and dump the dough out onto the floured surface. Quickly gather up the dough into a mass, knead briefly, and shape into a thick, flat rectangle. Wrap the dough in plastic wrap and refrigerate for at least 30 minutes or up to 1 hour. It is easiest to work with if it is chilled but not hard.
Make the filling
Preheat the oven to 350°F. Place the chicken thighs on a sheet pan, drizzle evenly with the oil, and season with salt and pepper. Roast until the chicken is cooked through, 25 to 30 minutes. Set aside to cool, then cut into large dice.
Meanwhile, in a saucepan, bring the stock to a simmer over medium heat. Melt the butter in a large Dutch oven over medium-low heat. Add the yellow onions, carrots, and celery and cook, stirring occasionally, until the onions are translucent, 10 to 15 minutes. Stir in the flour, reduce the heat to low, and cook, stirring constantly and not allowing the flour to brown, for about 2 minutes. Gradually add the hot stock while stirring constantly, then cook, stirring, until the sauce thickens, about 1 minute. Stir in the cream.
Add the chicken, peas, pearl onions, and parsley and stir to mix well. Season with salt and pepper, then remove from the heat and let cool.
Assemble the pie(s)
Increase the oven temperature to 375°F. If baking two pies, position racks in the top third and center of the oven. Transfer the filling to a 9-by-13-inch baking dish or divide the filling evenly between two dishes if making two pies.
On a floured work surface, roll out the dough into an 11-by-15-inch rectangle about 1/8 inch thick. If making two pies, roll out the second batch of dough. Center the dough over the dish(es) and press along the sides, decoratively crimping or fluting the edges.
Make the egg glaze
In a small bowl, whisk together the egg and water until blended. Lightly brush the dough with the glaze. Sprinkle the dough with salt and pepper. Cut three evenly spaced slits in the top to allow steam to escape.
Place the pie(s) on a sheet pan to catch any drips. Bake until the top is golden brown and the filling is bubbling hot, about 1 hour. Serve hot or warm.