Carefully pick off all stalks that seem tough. Use two large basins for washing the vegetable, lifting it from one basin into the other and changing the water five or six times, so that no grit remains. Put washed leaves into a very large saucepan (or else into two smaller ones, until cooking has begun, when all will easily go into one pan). Add no water, as there is sufficient moisture in the leaves. Turn and stir frequently at first, with a wooden spoon, until enough juice has been drawn out of the vegetable to prevent burning, after which it will cook in its own juices. Cook until nearly dry, which will take about 15 to 20 minutes, then rub through a rather coarse wire sieve and return to the pan with ¼ cupful of milk, an exceedingly small grate of nutmeg, 1 oz. butter and a pinch of salt. Stir till thoroughly hot and serve. Cream instead of milk, is an improvement.