Preheat oven to 350 degrees F. Line a baking sheet with a silicone mat or lightly grease. Set aside.
Into a large mixing bowl, combine the flours and baking powder together.
Add the water to the milk. Stir until mixed. The mixture should be warm, not hot.
Pour the liquid over the flour. Stir gently until mixed. Dough should be soft and just firm enough to be shaped.
Shape dough into a ball and turn onto a floured surface.
Roll dough out gently until about 1/2 inch in thickness. Cut out with a biscuit cutter, reusing dough scraps.
Place buns onto the prepared baking sheet.
Sprinkle with sesame seeds, pressing them down slightly.
Bake in oven for 12-14 minutes or until firm to the touch.
Remove buns from oven. Place buns on cooling rack.
While still hot, slice in half lengthwise with a bread knife, using a pot holder or cloth to hold buns while slicing. Let cool completely.
Store in the fridge or freeze for later.