Heat Milk and Butter in microwave for 30 seconds. When the mixture is warm, add Yeast and mix well.
Combine all bread ingredients and the milk mixture. Turn onto a lightly floured surface and knead until smooth and elastic.
Brush a large bowl with oil, place the dough and cover with a plastic wrap. Set aside in a warm place for 1 hour or until dough doubles in size.
Make 1 tablespoonful of 'Tsubu-an' into a ball, and make 12 balls.
Turn the dough onto lightly floured surface and divide the dough into 12 even portions. Flatten each portion to about 10cm disc, place 1 ball of 'Tsubu-an', and bring the dough together to enclose pinching the edges.
Place the bun, sealed side down, on baking paper on a baking tray. Repeat with the remaining dough, then set aside for about 1 hour to rise.
Preheat oven to 180°C. Add small amount of water to the remaining egg, brush the top of the buns with the egg mixture, and bake for 15 minutes or until nicely brown.
