To make the dressing, add all of the dressing ingredients except the fresh parsley to a blender or food processor and pulse until smooth. Pour the dressing into a jar with a lid and add the dressing, giving it a really good shake.
Place collards in a serving dish and massage with 1 tablespoon of olive oil and a pinch of salt. Layer the collards with red onion and avocado. Pour the dressing over the salad and toss. The dressing may be served on the side as well.