Cook the Chicken: Bring a pot of water to a boil and cook the chicken for 10–14 minutes. Alternatively, use an Instant Pot, slow cooker, or store-bought rotisserie chicken for convenience.
Prep the Veggies: While the chicken is cooking, finely chop the celery, onion, and scallions.
Shred & Mix: Once cooked, shred the chicken with two forks. In a large bowl, combine shredded chicken, chopped veggies, spices, and Greek yogurt.
Toss & Serve: Mix everything thoroughly until evenly coated. Serve on a sandwich, over a salad, or as a dip with crackers.