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 basil pesto, ranch seasoning mix, chicken broth, heavy cream, and grated Parmesan cheese until thoroughly combined and smooth.
03 - Pour the prepared sauce evenly over the chicken thighs, ensuring all pieces are adequately covered for maximum flavor infusion.
04 - Cover and cook on LOW setting for 4–6 hours, or until the chicken reaches an internal temperature of 165°F and becomes fork-tender.
05 - Transfer the chicken to a serving platter, spoon the remaining sauce over the top, and garnish with chopped fresh basil and additional Parmesan cheese if desired.