01 - Place the chicken thighs in the bottom of the slow cooker in a single layer, ensuring even distribution for consistent cooking.
02 - In a medium bowl, whisk together the pesto, ranch seasoning, chicken broth, heavy cream, and Parmesan cheese until thoroughly combined and smooth.
03 - Pour the sauce evenly over the chicken thighs, coating each piece completely.
04 - Cover and cook on LOW setting for 4 to 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, spoon sauce generously over the top, and garnish with fresh basil and additional Parmesan cheese if desired.