Prehear oven to 425. Grease a 10x15x1 inch jelly roll pan. Into a large mixing bowl, put yeast. Combine cream and boiling water and cool to lukewarm. Pour over yeast. Add sugar and salt. Let set for about 10 min. Then turn the 4 cups of flour into yeast mixture. Stir until a soft batter forms. Add as much of the remaining 1 cup flour to make a very soft dough, one that can be easily handled. Turn out onto the prepared jelly roll pan and pat dough evenly over the pan. Using a sharp knife, cut the dough lengthwise into 3 ribbons, then crosswise 8 times to mark off 24 rolls. Set in a warm place until risen, about 45 min. Bake until well puffed and golden brown about 30-32 min.Remove from oven and serve piping hot. We sometime brush a garlic butter over the top of the rolls the min. That they come out of the oven.