Chop the leek fine¬ly and stew it on a mod-er¬ate heat in the olive oil. Chop the meat in-to very small pie¬ces and add it to the soft¬ened leek. Stir and leave to cook for about 5 min. Sea¬son with the sa¬vo¬ry, the red pep¬per, the black pep¬per and the salt and add the to¬ma¬toes and the to¬ma¬to juice. Stew the mix¬ture at high heat un¬til it thick¬ens in fat. Then melt the but¬ter. Take three pas¬try sheets, spread each one gener¬ous¬ly with but-ter and put them one on top of the other. Cut the pas¬try sheets in¬to 4 equal parts. Put in each of them about 1 or 2 tea¬spoon¬fuls of the stuff¬ing. Roll the sar¬mi care¬ful¬ly and place them in the oiled tin. Should your pas¬try sheets tear up, roll care¬ful¬ly the sar-mi in another sheet. Re¬peat the same pro-ce¬dure un¬til you use up all the pas¬try sheets. Brush each of the sar¬mi with the beat¬en yolk. Bake for about half an hour in an oven pre¬heat¬ed to 180°C. When the sar-mi are al¬most baked, pour about 4 cm of hot wa¬ter in¬to the bak¬ing sheet and cov-er it with a tow¬el. In 5 min¬utes the dish is ready to serve.