Preheat the oven to 220°C. Lightly coat a 12-hole bun tin or muffin tray with cooking spray or a teaspoon of olive oil and put into the oven to heat. Mix together the flour, Parmesan and pepper in a medium bowl. Make a well in the centre of the flour mixture.
Whisk the eggs, egg white, milk and butter in another bowl until frothy. Pour into the well in the flour mixture and stir just until smooth. Stir in the spring onions.
When a drop of water dances and sizzles in the tin, it's hot enough. Spoon in the batter, dividing it evenly among the holes. Bake for 15 minutes. Reduce the oven temperature to 180°C and bake for a further 10 minutes or until golden and puffed up. Immediately remove from the tin and quickly make a small slit in the side of each puff to release the steam. Serve hot.
Some more ideas
*Replace the Parmesan with another grating cheese such as pecorino. *Add a few dried herbs such as dried thyme or oregano to the batter.
*By using a strong cheese in small amounts, you can have lots of flavour while keeping the fat and sodium content to a minimum. *Green onions, like other members of the onion family, contain allium compounds that may help relieve high blood pressure.