2 tbsp. extra-virgin olive oil
2 medium carrots, peeled and thinly sliced
2 celery stalks, thinly sliced
1 small onion, diced
2 cloves garlic, minced
Freshly ground black pepper
2 qt. organic chicken stock, homemade or store-bought
4 sprigs fresh thyme, plus 2 tsp. thyme leaves, divided
1 c. all-purpose flour
¼ c. freshly grated Parmesan, plus more for serving
½ c. whole milk
1 large egg, beaten
1½ c. rotisserie chicken, shredded
5 oz. baby spinach
In a large pot over medium-high heat, heat oil. Add carrots, celery, and onion and cook, stirring occasionally, until slightly tender, 4 minutes. Add garlic and cook, stirring occasionally, until fragrant, 1 minute, then season with salt and pepper.
Add chicken stock and thyme sprigs and bring to a boil. Reduce heat to low and simmer, partially covered, 10 minutes.
Meanwhile, make dumplings: In a large bowl, stir together flour, Parmesan, thyme leaves, milk, and egg with a fork until sticky dough forms, then season with salt and pepper. Drop dumpling mixture into soup 1 tablespoon at a time and let simmer until they rise to the surface, about 8 minutes. Stir in chicken and spinach and simmer until chicken is heated through and spinach wilted, 2 to 3 minutes.
Remove thyme sprigs from soup and season with salt and pepper. Serve in bowls garnished with Parmesan.