Leave the butter to soften. Activate the yeast with warm water, a little flour and the sugar. Mix all the ingredients for the dough, knead a soft, nonstick dough. Smear the ball of dough with oil, cover with plastic wrap, then with a towel and let rise until doubled in volume.
Then knead again and divide into 8 equal-sized balls. Roll out each ball thinly to about 11″ (28 cm) in diameter and smear generously with butter (I used my hands since the brush isn't precise).
Arrange the sheets on top of one another, without smearing the last one. Roll them out together a bit more and use a pizza slicer to cut out 16 triangles.
Leave for 15-20 min. to rise. In the meantime, turn oven on to heat up to 383°F (195 °C). Bake until golden, about 15-20 min.