Prepare ingredients: cube the apple, halve the grapes, shred and chop the rotisserie chicken, and measure the almonds, cranberries, yogurt, and garlic salt.
In a large bowl, combine the shredded chicken, cubed apple, halved grapes, slivered almonds, and dried cranberries.
Add the plain Greek yogurt and garlic salt to the bowl, then stir until everything is evenly coated. Season with salt and pepper to taste.
Spoon about a portion of the chicken salad onto each slider bun, then top with the bun lid. Secure with a toothpick if desired and serve immediately.
Notes
Use leftover or rotisserie chicken for convenience.