Cauliflower is part of the brussica family with a large white flower head that is grown and used in lots of dishes. It is great for people but can guinea pigs eat cauliflowers?!
However, it has renowned for making guinea pigs gassy so feed in tiny bits once or twice a week. They can have both the leaves and head. Remember that you must never feed cooked or frozen food to your guinea pig and it must be supplemented with hay and pellets.