Fill 3/4 of a pot (pan) with buckwheat groats, add salt, butter.
Pour over boiling water up to the top. Stir in carefully. And put into the well heated oven for 3-4 hours.
One hour before finishing, cover the pot with a large pan and turn upside down.
A half an hour before serving, put wet fabric round in order that kasha falls off from the pot sides. Serve with cold baked milk or butter.