Optional: Sear the chicken breasts in a pan over medium-high heat with 1-2 Tablespoons of oil for 2-3 minutes per side until lightly browned, then transfer to the slow cooker.

In a bowl, whisk together chicken broth, heavy cream, sun-dried tomatoes, garlic, thyme or oregano, red pepper flakes (if using), and cornstarch. Pour the mixture over the chicken in the slow cooker.

Cover and cook the chicken on the low setting for 5-6 hours, or until the chicken is fully cooked and tender. Avoid lifting the lid during cooking to prevent heat loss.

If desired, blend the sauce after cooking for a super smooth texture. Remove the chicken, blend the sauce until smooth, then return the chicken to the slow cooker and stir to coat.

Once the sauce has thickened, stir in the Parmesan cheese and let it simmer for an additional 5 minutes before serving. Garnish with fresh basil and extra parmesan, then taste for seasonings and adjust as needed.