Bring a large pot of water to a boil over high heat. Once boiling, carefully transfer the chicken breasts and return to a boil. Cover and remove from heat. Allow chicken to poach for approximately 25-30 minutes, or until chicken is fully cooked. Use tongs to remove cooked chicken from the pot and set aside on a clean plate to cool.
As the chicken cooks and cools, place the red onion, chopped celery, green onion, cilantro, pistachios, and dried cranberries in a large mixing bowl. Gently toss to combine.
In a separate, smaller bowl, combine the mayonnaise, Greek yogurt, honey, curry powder, garlic powder, onion powder, and salt. Add additional curry powder, or other seasonings, as needed.
Once the chicken is cool enough to handle either shred with two forks or chop into small cubes. Transfer to the bowl with the mixed onions and cranberries and stir in the mayonnaise mixture until fully combined.