Sift the flour onto a work surface. Knead with salt (1), milk (1), egg and oil to form a firm, smooth dough. Cover with a kitchen towel and rest briefly.
Heat the butter. Sift in the semolina and fry until golden brown, stirring throughout. Add the milk (2) and let the semolina swell for about 8 minutes. Season the quantity with salt.
Roll out the pasta dough thinly on a floured surface. Spread the semolina mixture on the dough sheet, leaving a margin of 1 cm. Roll up and press the edges firmly until smooth. Wrap the dough roll in a kitchen towel. Loosely tie the ends of the cloth.
Heat salted water in a large saucepan. Place the roll of dough in it at a low temperature for about 15 minutes. Remove and drain. Remove from the dish and cut diagonally into slices about 2 cm thick.
The semolina snails are excellent with roasts and stews with a lot of sauce.