Prepare the chicken: Chop or shred the cooked chicken into small, bite-sized pieces. If using leftover chicken, make sure it is properly chilled before mixing.
Chop the vegetables and grapes: Finely chop the celery and green onions. Cut the grapes in half so they are easier to eat.
Make the dressing: Stir together the mayonnaise, curry powder, lemon juice, honey, salt, and black pepper until smooth.
Taste the dressing: Taste it before adding it to the chicken and add a little more curry powder if you want a stronger flavor.
Combine the chicken and mix-ins: Add the chicken, celery, grapes, green onions, and optional nuts to a large bowl.
Add the dressing: Pour the dressing over the chicken mixture and gently stir until evenly coated.
Adjust the texture: Add a spoonful of mayonnaise if it feels too dry, or a little more chicken if it is too creamy.
Chill the salad: Cover and refrigerate for at least 30 minutes so the flavors can come together.
Serve: Give the salad a gentle stir, taste for seasoning, and serve.