01 - In a large bowl, whisk together buttermilk, mayonnaise, ranch seasoning, minced garlic, olive oil, dried parsley, black pepper, paprika, and salt until smooth and well combined.
02 - Add chicken cubes to the marinade, tossing to coat evenly. Cover and refrigerate for at least 30 minutes, up to 2 hours for deeper flavor penetration.
03 - Preheat grill or grill pan to medium-high heat. If using wooden skewers, soak them in water for 30 minutes prior to threading.
04 - Thread marinated chicken pieces onto skewers, leaving small space between each piece for even cooking.
05 - Lightly oil grill grates. Place skewers on grill and cook for 5–7 minutes per side, turning once, until chicken reaches internal temperature of 165°F and develops nice grill marks.
06 - During the last 2 minutes of grilling, sprinkle Parmesan cheese generously over skewers. Close grill lid to help cheese melt. Remove from heat and garnish with fresh parsley if desired.