Warm the oil in a skillet over medium heat. Add the “Chicken” and season with salt and pepper. Cook until lightly browned, about 4-5 minutes. Transfer to a bowl and refrigerate until cooled throughout.
In a mixing bowl, combine celery, scallions and herbs. Once “Chicken” has cooled, add to the bowl.
In a small bowl, whisk together the mayonnaise, lemon juice and mustard. Add to the “Chicken” mixture and mix gently until combined. Season with salt and pepper to taste. Refrigerate until ready to serve.