Place all the dressing ingredients in a clean jar. Close the lid and shake until the ingredients emulsify and become creamy. Alternatively, place ingredients in a bowl and whisk well. Taste and adjust seasoning, or add more olive oil for extra richness. Store in fridge until ready to use. Can be made several days in advance.
Place the chickpeas, cucumbers, tomatoes, and onions in a large bowl. Drizzle on some of the dressing and toss gently. Then top with feta and avocado. Serve with a sprinkle of parsley and extra dressing on the side.
