Dice the chicken breast into bite-sized pieces and finely chop the carrots, celery, and onion.
In a medium pot, heat the olive oil over medium heat and sauté the carrots, celery, and onion until softened, about 5 minutes.
Pour in the chicken broth and add the fresh thyme and parsley, bringing the mixture to a gentle boil.
Add the diced chicken to the pot, then reduce the heat to a simmer.
In a small bowl, whisk together the flour, baking powder, sea salt, and black pepper.
Stir the Greek yogurt into the dry ingredients until a thick dough forms.
Using a small spoon, drop rounded tablespoons of the dough into the simmering broth.
Cover the pot tightly with a lid and simmer for 12 to 15 minutes without lifting the lid until the dumplings are cooked through and fluffy.
Ladle the chicken and dumplings into a bowl and serve immediately.