Cut the butter into small cubes and put it in the refrigerator until required.
Mix the flour, salt, black pepper and chili flakes together.
Add the cold, cubed butter into the flour and using your hands, mix till it resembles a coarse sand-like texture.
Directly grate the cheese into the flour and start to bring the mixture together into a dough. Slowly, add milk to form a semi-soft dough.
Place the dough in a bowl, cover and put it away in the refrigerator for 15 minutes.
Meanwhile, pre-heat the oven to 180 degree C. Line a baking tray or pan with baking paper.
Remove the dough, form equal sized balls and place each ball, slightly flattened on the tray.
Brush the surface of the cookies with milk, and sprinkle the sesame seeds on top. Bake for 20-25 minutes until golden brown.
Remove and let them cool, then pack airtight.