Savory Chicken In Bread

3 cups all-purpose flour, plus more as needed
1 1/2 teaspoons kosher salt, plus more as needed
1/2 teaspoon sugar
12 tablespoons (1 1/2 sticks) unsalted butter, cut into pieces
1 tablespoon olive oil
2 celery stalks, peeled and chopped
1 medium carrot, peeled and chopped
1 medium onion, chopped
1 tablespoon chopped fresh rosemary
1 3- to 3 1/2-pound chicken, giblets and excess fat and skin removed, bird patted dry
Freshly ground black pepper
1 large egg, beaten

For the Dough: 1. To make the bread dough, combine the flour, salt, and sugar in the bowl of a stand mixer  fitted with the paddle attachment. Add the butter and mix with the paddle, stopping the mixer occasionally to break up bigger chunks of butter with your hand. Add 1/2 cup water and continue mixing until the dough begins to come together. 2.At this point, turn off the mixer and switch to the dough hook (scraping all the dough off the paddle first, of course). Knead the dough with the hook until it comes together in one mass, 1 to 2 minutes. 3. Turn the dough out onto a lightly floured surface and continue to knead it by hand, pushing it away from you with the heel of your hand, folding it over, giving it a quarter turn, and pushing it away again until it feels nice and elastic. If the dough is very sticky, add a little more flour to it as you knead. Wrap the dough in plastic wrap and refrigerate it for at least 30 minutes. For the Chicken: 4. Meanwhile, heat the olive oil in a medium skillet over medium heat. Add the celery, carrot, onion, rosemary, and a pinch of salt and cook, stirring occasionally, until the vegetables are just tender but not colored, 8 minutes. Let cool. 5. Clip the chicken wings off at the body and save for making stock or discard. Season the chicken liberally inside and out with salt and pepper. Stuff the bird with the cooled vegetables and tie the legs together with kitchen twine.
Heat the oven to 400° F. 6. On a very lightly floured surface, roll the dough out to 1/8-inch thick; this will take some muscle. If the dough is very stubborn, let it rest for a few minutes before trying to roll it some more. Put the chicken on the dough breast side down and wrap the dough up and around the bird, encompassing it completely and overlapping the dough. (If there is a lot of overlap, trim the dough.) Pinch the seams together to keep them closed. Turn the bird over and put the bird seam side down on a baking sheet. Brush the dough all over with the egg and sprinkle it lightly all over with salt. 7. Bake until the chicken is cooked through and the bread is a lovely golden brown, 1 to 1 1/2 hours, depending on the size of the chicken (an instant-read thermometer inserted through the crust into the breast should read 170° F). 8. Let cool for at least an hour, preferably 2, before tearing it apart and serving. Recipe courtesy of Barbara Lynch, “Stir: Mixing It Up in the Italian Tradition,” 2009.