Roast beet: Preheat oven to 400ºF. Rinse the beet and wrap in foil. Roast for 1 hour, then remove and let cool.
Cut the cooled beet into inch size pieces and add to a food processor with the chickpeas, tahini, olive oil, garlic, thyme, salt, black pepper, cumin and cayenne. Pulse until combined, scrape down the sides and run on high for 2 minutes.
Scrape down the sides again and turn back on high. Slowly drizzle the ice water into the running food processor until the hummus becomes smooth. Dig in!