In your food processor, add 2 of the avocados, the chickpeas, tahini, the lemon juice, garlic, salt and pepper. Puree until the chickpeas break down and the mixture starts to come together (it probably won’t be smooth at this point!). Make sure to scrape the sides with a spatula. Drizzle in the ice water. Blend it for a minute or two – just let it go! Once the water is in, the hummus should really start to get smooth – if you need a little more water, add it 1 tablespoon at a time.