01 - Place the chicken thighs in the bottom of the slow cooker, arranging them in a single layer for even cooking.
02 - In a medium bowl, whisk together the pesto, ranch seasoning, chicken broth, heavy cream, and Parmesan cheese until smooth and well combined.
03 - Pour the prepared sauce evenly over the chicken thighs, ensuring all pieces are coated.
04 - Cover and cook on LOW setting for 4–6 hours, or until the chicken reaches an internal temperature of 165°F and is tender throughout.
05 - Transfer the chicken to a serving platter and spoon the sauce generously over the top. Garnish with fresh chopped basil and additional Parmesan cheese if desired.