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 celery. Cook for another 5 minutes until the vegetables begin to soften.
Add the dried thyme, oregano, and red pepper flakes (if using). Stir to combine and cook for 1 minute until fragrant.
Pour in the chicken broth and bring the mixture to a boil. Reduce heat and let it simmer for about 10 minutes.
Stir in the shredded chicken and heavy cream. Cook for an additional 5 minutes, allowing the soup to thicken slightly.
Add the frozen peas and season with salt and pepper to taste. Cook for another 2-3 minutes until the peas are heated through.
Serve hot, garnished with fresh parsley.