Heat olive oil in a large pot over medium heat.
Add chicken and cook until golden brown. Remove and set aside.
In the same pot, sauté onion and garlic until fragrant.
Add oregano and red pepper flakes, stirring for 30 seconds.
Pour in chicken broth and bring to a simmer.
Add sun-dried tomatoes and cooked chicken, simmering for 10 minutes.
Stir in heavy cream, Parmesan cheese, and thyme.
Add spinach and let wilt for 2 minutes.
Season with salt and pepper, then serve hot.