Shred your cooled cooked chicken using two forks and place it in a large mixing bowl.

Finely chop the red or green onions and pat dry and dice the dill pickles. Toss with the shredded chicken.

In a separate bowl, whisk together Greek yogurt, mayonnaise, relish, and mustard. Incorporate chives and dill, seasoning with salt and pepper.

Pour the dressing over the chicken and vegetable mixture. Fold gently to combine.

Taste and adjust seasoning as necessary.

Transfer to an airtight container and chill for at least 2 hours, preferably overnight.