In a large pot, heat the olive oil over medium heat. Add the diced onion, carrots, and celery, and sauté until the vegetables are tender, about 5 minutes.
Stir in the minced garlic, thyme, and oregano, and cook for another minute until fragrant.
Pour in the chicken broth and add the chicken breasts. Bring the mixture to a boil, then reduce the heat and let it simmer for 20 minutes, or until the chicken is cooked through.
Remove the chicken from the pot and shred it using two forks. Return the shredded chicken to the pot.
Stir in the heavy cream and bring the soup back to a gentle simmer.
Add the potato gnocchi to the soup and cook for about 5 minutes, or until the gnocchi float to the top.
Add the chopped spinach and stir until wilted. Season the soup with salt and pepper to taste.
Serve hot, garnished with grated Parmesan cheese if desired.
Notes
For a lighter version, you can use half-and-half instead of heavy cream.