In a large mixing bowl, whisk together the Greek yogurt, light mayonnaise, Dijon mustard, honey, lemon juice, and 1 teaspoon of the Everything Bagel seasoning. Season with a pinch of salt and pepper, then whisk until smooth.
Add the diced chicken, grapes, apple, and celery to the bowl. Gently stir until everything is evenly coated with the dressing.
Fold in the chopped pecans.
Sprinkle the remaining 1 teaspoon of Everything Bagel seasoning over the top just before serving.
Serve on pumpernickel or rye bread, on cucumber slices, or enjoy it on its own.