• Preheat the oven to 180C/160C Fan/Gas 4.

• To make the granola, whisk the egg whites, honey, orange zest, cinnamon or mixed spice and salt together in a large bowl. Add the oats, bran flakes and seeds and stir together, making sure everything is evenly coated.

• Tip the mixture onto a large, non-stick baking tray and bake for 30 minutes. Add the raisins, give everything a good stir, then bake for a further 10 minutes.

• Remove from the oven and leave to cool completely. When the granola is cool, scrunch it with your hands to break up any large pieces.

The granola will keep, in an airtight container, for two weeks. Raisins tend to be the most popular dried fruit, but you can use a mixture. Try chopped dried apricots, figs or cranberries.