Pour milk, water and sugar into a jar, stir in yeast and leave for a few minutes.
Add flour, semolina and salt into a large bowl and whisk until combined. Make a well in the centre and pour in the wet ingredients. Stir together as much as you can with a wooden spoon and then tip the dough out onto a clean work surface and knead for about 10 minutes by hand.
Grease the large bowl and dough with butter and place the dough back into the bowl, cover with cling film and leave to rise in a warm place until doubled in size. This should take around 45 minutes to 1 hour 15 minutes.
Once doubled in size, punch down the dough and give it a little knead. Break off small amounts of dough and flatten with your fingers.
Place chunks of mozzarella in the centre and wrap the dough around it. Place into a mini muffin tray and repeat with the remaining dough.
Cover tray with cling film and leave to rise for another 20 minutes in a warm place.
For the garlic butter, combine the butter, garlic and parsley in a bowl and stir until combined.
Brush garlic butter over the risen dough balls and place into a preheated oven at 180°C for 20-25 minutes until golden.
Remove from the oven and brush with more garlic butter. These are best enjoyed straight away.