First, prepare the filling. Put in bowl ricotta, parmesan and any easily melting cheese (like fontina), grated on a fine grater, 1 egg. Stir well, salt and pepper.
For the dough, pour the sifted flour in a slide onto the work table, add a pinch of salt and 4 eggs. Knead a hard elastic dough (knead for at least 10 minutes). If the dough is too tight, add a little olive oil. Wrap the dough in a clean towel and leave for 30 minutes.
Then roll out the dough into a thin layer and cut into squares. Put the filling in the middle, fold the square diagonally, pinch the edges and connect the ends, like with ordinary dumplings.
Dip the tortellini in a wide saucepan of boiling salted water.
While they are boiling, melt the butter in a saucepan, mix with half the marjoram. Remove the pop-up tortellini with a slotted spoon. Let the water drain well and place on a dish. Pour the finished tortellini with marjoram oil, sprinkle with chopped marjoram and serve hot.