Heat the oil in a large pot over medium heat. Add the onion, garlic, carrots, and celery. Cook, stirring occasionally, until the vegetables are tender, about 5 minutes.
Add the flour and cook, stirring constantly, for 1 minute. Gradually add the chicken broth, stirring until smooth.
Add the chicken, thyme, oregano, salt, and pepper. Bring to a boil, then reduce the heat to low and simmer for 25 minutes.
Add the frozen vegetables and simmer for 10 minutes.
In a medium bowl, whisk together the flour, baking powder, butter, and milk until combined. Drop tablespoon-sized balls of the dumpling dough into the simmering soup.
Cover and simmer for 10 minutes, or until the dumplings are cooked through. Serve hot.
Interesting Facts
The origin of chicken and dumplings is unknown, but it is believed to be of American origin.
Chicken and dumplings is often served with mashed potatoes, biscuits, or cornbread.
This dish is often served during the winter months as a comforting meal.