Heat the olive oil in a medium pot over medium heat and sauté the diced onion, carrots, and celery until the onions are translucent and fragrant.
Stir in 1 tablespoon of the whole wheat flour to coat the vegetables, then slowly pour in the chicken broth while stirring to create a slightly thickened base.
Add the dried thyme, sea salt, black pepper, and the cubed chicken breast to the pot, bringing the mixture to a gentle simmer.
In a small mixing bowl, combine the remaining whole wheat flour, baking powder, and Greek yogurt, stirring until a soft, uniform dough forms.
Using a small spoon, drop rounded tablespoons of the dough into the simmering broth, then cover the pot with a tight-fitting lid.
Simmer for 12 minutes without lifting the lid to allow the dumplings to steam and become fluffy, then garnish with fresh parsley before serving.