For the Soup:
3 tablespoons olive oil
6 boneless, skinless chicken thighs
salt and pepper to season chicken thighs
1 large yellow onion, coarsely diced
4 carrots, peeled and sliced
4 ribs celery, trimmed and sliced
1 clove garlic, minced
1 1/2 teaspoons dried thyme
2 quarts low-sodium chicken broth
1 bay leaf
1 cup frozen peas
1/4 cup finely chopped flat-leaf parsley
salt and pepper to taste

For the Dumplings:
1 cup all-purpose flour
1 1/2 teaspoons baking powder
1/2 teaspoon salt
1/4 teaspoon dried thyme
1/4 teaspoon fresh ground black pepper
1 tablespoon unsalted butter, cold
1 large egg, beaten
1/4 cup buttermilk, cold