Bring salted water to a boil in a medium saucepan, add the chopped beets and cook for 10 to 15 minutes until the beets have softened, and can easily be pierced with a fork. Drain and add to a food processor or blender with garlic, tahini, olive oil, and lemon juice, and puree until smooth and creamy. Serve with crudites such as celery and carrots, or whole-wheat pretzels or whole wheat pita chips.