Unroll the puff pastry and spread the whole surface with the garlic cream cheese.
Scatter the mozzarella over the top and season with freshly ground pepper, if you like.
Roll the puff pastry up into a long log - starting from one of the long edges - and place it seam side down.
Make slanted cuts roughly halfway through the dough at intervals of about 5-6 cm - and press the dough down lightly with the back of a knife between each cut.
Now curve the log into a ring and pinch the ends firmly together at the join.
Brush with the beaten egg and sprinkle with sesame seeds, if using.
Bake the puff pastry wreath in a preheated conventional oven (top and bottom heat) at 200°C for about 22-25 minutes - on the middle shelf.
Let the bread rest for 5-8 minutes before serving.