If I just want to do one at a time I also wrap in tissue and pop in microwave. But if I want to do a large batch and freeze some for another time, I peel,chop and wash then put them in my electric steamer. Depending on amount can take 10-20 minutes and most if not all the nutrients are retained plus you can use some of the water in the bottom of the steamer when mashing to make it even softer
