Heat the olive oil in a large pot over medium heat and sauté the onion, carrots, and celery until they begin to soften.
Add the diced chicken breast and minced garlic to the pot, cooking until the chicken is opaque on all sides.
Pour in the chicken broth and add the dried thyme, sea salt, and black pepper, then bring the mixture to a gentle simmer.
In a separate mixing bowl, whisk together the whole wheat flour, baking powder, and dried parsley.
Stir the Greek yogurt into the flour mixture, adding a tablespoon of water if needed to form a thick, tacky dough.
Using a small spoon, drop rounded portions of the dough directly onto the surface of the simmering broth.
Cover the pot with a tight-fitting lid and steam the dumplings for 10 to 12 minutes without lifting the cover.
Serve the chicken and vegetables in bowls, topped with the light and airy dumplings and a ladle of the herb-infused broth.