Warm milk and butter in microwave until temperature reached ~100-110ºF, or the temperature your instant yeast requires to activate. Do not overheat as it will kill the yeast.
In the bowl of a stand mixer or a large mixing bowl, add warm milk mixture and yeast, the mix to combine. Add sugar, egg, and salt. Whisk to combine.
Add bread flour. Using either your hands or a dough hook on a stand mixer, knead dough until bread flour is completely incorporated. The dough should be slightly sticky. If dough is too wet, add flour 1 tbsp at a time.
Transfer dough to a large, lightly greased bowl. Cover with a towel. Let dough rise in a warm spot for 1 hour.
After and hour, the dough should double in size. Punch dough to release air bubbles. Transfer dough to a lightly floured surface. Roll dough into a long tube, then cut tube into 12 pieces keeping them as even as possible (cut tube in half and then each have into quarters. Cut each quarter into 3 pieces)
Working with one piece of dough at a time, lightly knead the dough piece. Slightly flatten and place one mozzarella cube in the center. Gently form a dough ball around the cheese making sure to seal the bottom of the dough ball. Place sealed side down in a greased 9x13 baking dish. Repeat for each dough piece.
Once all 12 cheesy dough balls have been placed in the 9x13 pan, cover with a towel and let rise for 1 hour.
Preheat oven to 350º. While oven is preheating, make the garlic butter compound by mixing the melted butter, salt and minced garlic. Generously brush the compound over the top of the dough balls.
Bake for 20 minutes.
Serve rolls warm. Enjoy!