Hey I learned this thing about sweet potatoes: the lower and slower you cook them, the sweeter they turn out. These are my simplified instructions, since I don't have a sous-vide and don't even want to mess with aluminium foil. Though I might play around with baking them in a covered dish.
I bake four sweet potatoes at a time, cut them in half, and keep them in a container in the fridge. Half a sweet potato per dinner bowl, unless they're small or I'm hungry.
four sweet potatoes
Heat oven to 275 degrees. Scrub the sweet potatoes and put them in the oven in a baking pan. Bake until tender when poked with a fork or knife, at least an hour and maybe longer.