I found this recipe on recipesecrets.net and I didn't have a lot of the ingredients on hand, so I converted it to what I did have and it turned out great!
You will need:
1/3 cup mayo
2 Tablespoons cider vinegar
1 Tablespoon dijon mustard
2 cooked boneless and skinless chicken breasts, diced (a generous 2 cups)
1/2 -3/4 green apple, cored and cut into medium dice
Salt and pepper, if desired
handful of red grapes, quartered
handful of walnuts (optional)
In a large bowl, whisk together the mayonnaise, cider vinegar and Dijon mustard to form a dressing.
Toss everything together, taste and adjust the seasoning if desired.
Chill before serving.
This makes about 1 quart chicken salad.
Recipe adapted from http://www.recipesecrets.net