Combine stock, celery, carrots, onion, parsely, pepper, and chicken in a large Dutch oven. Bring to a boil on the stove. Reduce heat to simmer. Simmer for 20 minutes, or until the chicken is cooked through.
Remove the chicken thighs. Cool enough to handle. Dice the meat into bite sized pieces. Discard the bones and skin. Return diced chicken to stock mixture.
In a mixing bowl, combine the flour, baking powder and salt. Stir in milk and oil to form a stiff dough.
Drop the dough by teaspoonfuls into the stock mixture. Cover and simmer for 20 minutes.
Cool slightly. Serve in bowls.