Prepare the chicken by cooking it using your preferred method. Let it cool, then shred or dice it into bite-sized pieces.
In a large mixing bowl, combine the shredded chicken, diced celery, halved grapes, sliced almonds, and chopped green onions. Gently fold the ingredients together.
In a separate bowl, mix the mayonnaise, Greek yogurt, Dijon mustard, honey, garlic powder, onion powder, salt, and black pepper until smooth and creamy.
Pour the dressing over the salad mixture and gently fold until all ingredients are coated. Cover and refrigerate for at least 60 minutes before serving.