In a large pot, heat the olive oil over medium heat. Add the diced onion and sauté for about 3-4 minutes until translucent.
Stir in the minced garlic, sliced carrots, and celery. Cook for another 5 minutes until the vegetables are tender.
Add the chicken breasts to the pot and pour in the chicken broth. Stir in the dried thyme, oregano, and red pepper flakes if using. Bring to a boil, then reduce the heat and 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 frozen peas. Simmer for an additional 5 minutes, allowing the soup to thicken slightly. Season with salt and pepper to taste.
Serve hot, garnished with fresh parsley.