Heat olive oil in a large pot over medium heat. Add onion and cook 3–4 minutes until soft. Stir in garlic and cook 30 seconds until fragrant.
Pour in chicken broth. Add Italian seasoning, paprika, salt, pepper, and tomato paste (if using). Stir well.
Add chicken breasts to the pot. Bring to a gentle simmer, cover, and cook 15–18 minutes until cooked through.
Remove chicken, shred with two forks, then return to the pot.
Lower heat to low. Whisk in softened cream cheese until smooth, then stir in heavy cream, parmesan, and sun-dried tomatoes.
Stir in spinach and cook 1–2 minutes until wilted. Taste and adjust seasoning. Serve hot with fresh herbs if desired.