Dice the chicken breast into bite-sized pieces and season lightly with a pinch of the salt and pepper.
Heat the olive oil in a medium pot over medium-high heat and sauté the chicken until golden brown on all sides.
Add the diced carrots, celery, and onion to the pot, cooking for 5 minutes until the vegetables begin to soften.
Stir in the chicken broth, dried thyme, and dried parsley, then bring the mixture to a gentle simmer.
In a small mixing bowl, combine the whole wheat flour, Greek yogurt, baking powder, and the remaining salt and pepper to form a thick, sticky dough.
Using a small spoon, drop rounded tablespoons of the dough directly into the simmering broth.
Cover the pot with a tight-fitting lid and reduce the heat to low, simmering for 12 minutes without lifting the lid.
Remove from heat once the dumplings are puffed and cooked through, then serve immediately in deep bowls.