Put the cooked macaroni, chicken, onion, and grapes in a large bowl. Set aside.
Place the avocado, non-dairy milk, mayo, dill, salt, and pepper in a blender, and blend on high until smooth.
Pour the dressing over the other ingredients, and mix together to coat.
Refrigerate until ready to serve.
Notes
Store leftover pasta salad in an airtight container. It should stay fresh for about 3 days.Use whatever brand of gluten free pasta that works for your dietary needs.Feel free to leave the chicken out if you like. You could add some chickpeas instead for some extra protein.