Mix the flour, warm milk, yeast and salt in a bowl until it forms a dough and let it rest in a warm place for a couple of hours. In the meantime mix your kinds of cheese with a whole egg and form two balls. Cover them and let them rest in the fridge until the dough has rested. After a couple of hours, split the dough into two halves a take one. Roll out the dough, put one of the cheese balls in the middle and wrap the dough around it and make sure that the ball is well sealed. Preheat a big pan (without any oil or anything!). Press the ball to flatten it a bit and roll it out until you have pizza-shaped bread that fits the pan. Put the bread on the pan and "fry" it for five minutes on each side (optionally you can you a lid as well). When the bread is done, grease the top side with a bit of butter, to prevent crusting. Serve either warm or cold. Repeat the process with the rest of the dough and the cheese mixture and you will and up with two loaves of this amazing bread.