To a food processor, add the mayo, yogurt, avocado, vinegar, lemon zest and juice, garlic, dill, basil, scallions, and salt.
Puree the ingredients in the food processor until a thick, creamy, smooth dressing forms.
In a large bowl, shred the chicken and add the minced onion. Pour the dressing on top.
Stir to combine and until the chicken is thoroughly coated in the dressing.
