Cook potatoes in jackets until just barely done;  cool and skin.  Dice into buttered casserole.  Cook onions in butter until soft and add entire mixture to potatoes.  Combine soup and Velveeta and cook over low heat until cheese melts and mixture is smooth.  Pour over potatoes and mix well.  Add almonds and season to taste.  Cook at 350°  until hot.  May be made the day before and reheated in double boiler.  Serves 12.