In a large pot, heat the olive oil over medium heat. Add the diced onion and sauté until translucent, about 5 minutes.
Stir in the minced garlic, sliced carrots, and sliced celery. Cook for an additional 3-4 minutes until the vegetables begin to soften.
Add the chicken breasts to the pot, then pour in the chicken broth. Stir in the dried thyme, dried oregano, and red pepper flakes if using. Bring to a boil.
Reduce the heat to low, cover, and simmer for 20-25 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 another 5-10 minutes until the soup is heated through. Season with salt and pepper to taste.
Serve hot, garnished with fresh parsley.