Sift the buckwheat flour, spread it out in a large frying pan, and fry it slightly to colour it. Then put it in an earthenware pot with 1 teaspoon of salt, 1 tablespoon of butter and just enough water to cover. Put the lid on the pot and cook in a slow oven for 2 to 3 hours. It is advisable to stand the pot in a tin containing a little water, so that it will not catch. Serve with either cream or melted butter.