Cube into 1 inch pieces and steam for 15 minutes on stove, or until tender when pierced with a fork.
Remove from heat and mash with half and half, butter, ½ tsp of salt and pepper, each and rosemary. (I usually put this in the oven to stay warm while I finish the rest of the meal.)
Recipe by momwithagoldenfork at http://www.momwithagoldenfork.com/dinnertime/strip-steak-with-sweet-potatoes-and-spinach/