Combine the flours, soda, mustard, salt and cheese in a bowl. Whisk together the milk and sour cream. Stir into the flour and mix to form dough.
Knead gently on a floured surface before lightly rolling out to a 20 x 25cm rectangle.
Spread with VEGEMITE then roll up like a Swiss roll from the long side. Cut into 12 pinwheels and place, cut side up each into a 12 x ⅓ cup capacity greased muffin pan.
Sprinkle over the extra cheese and bake in a hot oven 200°C for 15-20 minutes or until golden brown. Serve warm.