Preheat grill or grill pan to medium-high heat.
Thread cubed chicken onto wooden or metal skewers, leaving a small space between pieces.
Brush chicken skewers with olive oil and then coat generously with BBQ sauce.
Place skewers on the grill and cook for 5-7 minutes per side, or until internal temperature reaches 165°F (74°C).
In a food processor or blender, combine avocado, Greek yogurt, cilantro, lime juice, garlic, salt, pepper, and water. Blend until smooth and creamy.
In a large bowl, toss the chopped romaine, black beans, corn, cherry tomatoes, and red onion.
Divide the salad mixture into four plates or bowls.
Remove chicken from skewers or place skewers directly on top of the salad beds.
Drizzle the creamy avocado dressing over each portion and serve immediately.