Heat up the milk and dissolve the yeast, sugar, and 1 tbsp flour in it, leave to bubble. Sift the flour and salt, make a well and pour in the egg and effervescent yeast.
Start kneading until you get a soft dough that doesn't stick to the hands. Divide up the dough into balls of about 2 oz (50 g) each (12-13 balls) and leave the dough to rest for 10-15 min.
In the meantime, make the filling by combining the 3 cheeses with the egg white and stirring well.
Roll out each ball into a thin sheet on a well-floured counter, smear 1/2 the sheet with the cheese mixture, cut the other 1/2 into strips (see photo). Then wrap it up into a roll, starting from the side with the filling, and arrange the roll into a spiral.
Arrange the spiral rolls together in a tray about 12″ (30 cm) in diameter, laid out with baking paper. Leave thus formed loaf to rise in a warm area for 30-40 min. Smear it with egg yolk and sprinkle with sesame seeds.
Bake in a preheated 392°F (200 °C) oven until ready.