Roast chicken according to recipe linked in body of post
Slice grapes and green onion
Chop celery and tarragon
Crush garlic cloves and mix into mayo along with chopped tarragon and lemon juice
Once chicken is cooked and cooled, shred the meat with your fingers or two forks
In a large mixing bowl combine shredded chicken, grapes, celery and green onion and stir
Pour in mayonnaise and fold together until all mayo is well incorporated
Serve on sliced whole grain bread with a piece of butter lettuce or in a butter lettuce cup for chicken salad lettuce wraps