Combine the milk and yeast in a mixing bowl (this one’s my favorite) and stir until dissolved. Mix in the sugar, butter, and egg, then add the salt and flour.
Knead for 6 to 8 minutes, or until the dough is smooth and elastic.
Set aside in a warm place to rise in a covered bowl for 60 to 90 minutes.
Punch down the dough and divide into 8 equal balls. Press each ball into a 3-inch circle. Rise for 30 minutes, or until the buns are round and puffy. Brush the tops of the buns with the egg/water mixture, and sprinkle with sesame seeds.
Preheat the oven to 375ºF. Bake for 14 to 16 minutes, or until the buns are golden brown. Cool on a wire rack. These are best if eaten within 1 to 2 days of being made– store leftovers in an airtight container.