Sweet potato tortillas

Cook the potatoes in the skin the day before, peel and pass through a meat grinder, then knead thoroughly with flour, vanilla sugar, egg, vegetable oil and salt. Dissolve the yeast in sweetened milk, mix with 1 tablespoon of flour and allow to rise. When suitable, mix with potato dough and put more for lifting. The dough should be pretty cool. On a board lubricated with vegetable oil, roll out a finger-thick layer of potato dough with a rolling pin, also lubricated with oil, from which you cut circles into a glass. Brown the potato tortillas on both sides in large quantities of well-heated vegetable oil, then discard on a sieve, allow to drain excess oil and sprinkle with vanilla sugar. Serve the potato tortillas to the table hot.