Pour 6 cups chicken broth into a large pot or Dutch oven. Add the celery pieces and the halved onion.

Nestle the halved chicken breasts into the liquid. Bring to a boil over medium-high heat.

Once boiling, lower the heat to maintain a gentle simmer. Cover partially and cook for about 15 minutes, or until the chicken is cooked through.

While the chicken simmers, make the dumpling dough: whisk 3 cups flour, 1 tbsp baking powder, and 1¼ tsp salt in a medium bowl.

Stir in 1 cup plus 2 tbsp milk gently until a shaggy dough forms. Don’t overmix.

Lightly flour a work surface. Turn out the dough and roll it to roughly ¼-inch thickness. Use a pizza cutter or knife to cut strips or squares 1–2 inches wide.

Remove the cooked chicken from the pot and place it on a cutting board. Discard the celery and onion from the broth. Bring the broth back to a gentle simmer.

Carefully drop the dumpling pieces into the simmering liquid, stirring gently to separate and distribute them.

Simmer the dumplings for 20–30 minutes, stirring occasionally so they don’t stick together. Test one for doneness—dumplings should be tender and cooked through.

While dumplings cook, shred or chop the chicken into bite-sized pieces. Add the chicken back to the pot and warm through for a few minutes.

Taste the broth and season with salt and pepper to your liking. Serve hot.