Preheat the oven to 200 C, 180 Fan, Gas 6. Line a 12 bun Muffin tray with 12 cases.
Mix the flours, baking powder, bicarb, salt, mustard powder and cheese in a large mixing bowl with a fork.
Beat together the remaining ingredients in a large measuring jug and pour into the dry ingredients mixing lightly with your fork. The best muffins are made from lumpy batter.
Pour into the muffin cases and cook for 20 minutes. Quickly take them out of the oven and put a little cheese and a sprinkling of Worcestershire sauce on each one. Return to the oven for 5 minutes.
Put on a baking tray to cool and eat while still warm but not hot.