Heat olive oil in a large pot or Dutch oven over medium heat. Add diced onion, carrots, and celery. Sauté for 5–6 minutes until softened.
Add garlic and cook for another minute until fragrant.
Add chicken, chicken broth, thyme, parsley, salt, and pepper. Bring to a boil, then reduce heat and simmer for 20 minutes, or until chicken is cooked through and tender.
Remove chicken, shred it with two forks, and return to the pot.
Optional: To thicken the soup, melt butter in a small pan, whisk in flour, and cook for 1–2 minutes to make a roux. Stir into the soup and simmer for 5 minutes.
Stir in heavy cream if using.
In a bowl, mix dumpling flour, baking powder, salt, milk, and melted butter until just combined.
Drop spoonfuls of dumpling batter onto the simmering soup. Cover and cook for 15 minutes without lifting the lid, until dumplings are fluffy and cooked through.
Garnish with fresh parsley and serve warm.
Notes
Don’t overmix the dumpling dough to keep them light and fluffy.
For extra flavor, use bone-in chicken and remove bones before serving.
You can add peas or green beans for more vegetables.
Soup thickens more as it cools; reheat gently and add broth as needed.