I'm perplexed. I've seen a lot of recipes for sweet potatoe souffle. They all call for various amounts of mashed or whipped sweet potatoes which means they are already cooked. But they don't specify exactly how they reach that condition. So how do you cook them? Do you oven roast them and then scoop out the shells? Do you peel them first? Do you boil them, peeled like regular potatoes? What say you Chowhounds?