Orange and Rosemary Shortbread

These  biscuits pack a real punch of orange flavour and a subtle hint of rosemary so kids will probably love them just as much as adults. They'd be really nice popped into little bags for teachers gifts or even for foodies in hampers. I've decorated mine with some rosemary flowers too although I'm surprised that I still had some flowering in the garden. It must be all this mild weather. These were glazed with an egg wash, but I don't think they really need it. So leave it out if you want to. 

Ingredients:

225g unsalted butter, softened

150g granulated sugar

zest of one orange, finely grated

1 tsp salt

2 tbsp fresh rosemary

1 free-range egg, separated

275g plain flour

2 tbsp orange juice (squeezed from the orange)