Heat the milk and butter on medium heat for 2-3 minutes until the butter has melted. In a bowl, combine 450g flour, 0.5 teaspoon salt, 70g sugar, and egg. Make a well in the flour and crumble the yeast into it. Pour the warm milk-butter mixture into the well and knead from the center outward until you have a smooth dough. If it's still sticky, gradually add the remaining 50g flour until the dough is easy to handle. Cover the bowl and let it rise in a warm place for 1 hour.
Roll out the dough into a rectangle and roll it up tightly from the long side. Cut into 2-3 cm thick slices. Place the slices cut-side down in a greased baking dish. Cover and let rise for 30 minutes.
Preheat the oven to 180°C (356°F). Bake the rolls with top and bottom heat for 15-20 minutes until golden brown.