Heat the olive oil in a medium pot over medium heat and sauté the diced onion, carrots, and celery until the vegetables begin to soften.
Pour in the chicken bone broth and add the dried thyme, sea salt, and black pepper, bringing the mixture to a gentle simmer.
Cut the chicken breast into bite-sized pieces and carefully add them to the simmering broth.
In a small mixing bowl, combine the whole wheat flour, baking powder, and half of the fresh parsley with 1-2 tablespoons of water to form a thick, tacky dough.
Drop small spoonfuls of the dough into the pot, ensuring they sit on top of the liquid.
Cover the pot with a tight-fitting lid and steam for 10 to 12 minutes until the dumplings are fluffy and the chicken is fully cooked.
Remove from heat, gently stir in the Greek yogurt to create a creamy base, and garnish with the remaining fresh parsley before serving.