Heat olive oil in a large pot over medium-high heat. Season chicken with salt and pepper, then cook for 5–6 minutes per side until golden. Remove and shred.
In the same pot, add onion and garlic. Sauté for 2–3 minutes until fragrant. Stir in sun-dried tomatoes, basil, oregano, and red pepper flakes.
Pour in chicken broth, scraping up any browned bits. Bring to a simmer, then reduce heat and cook for 10 minutes.
Stir in heavy cream and Parmesan until smooth. Return shredded chicken to the pot.
Add spinach and cook for 2–3 minutes until wilted. Season with salt and pepper to taste.
Ladle into bowls and garnish with fresh basil or parsley. Serve with crusty bread.