Lemon and passion fruit shortbread biscuits

Ingredients

225g/8oz unsalted butter, at room temperature
75g/3oz caster sugar
275g/10oz plain flour, sifted
75g/3oz fine semolina
1 tsp grated lemon zest
flesh and seeds from 1 ripe passion fruit
pinch salt
extra caster sugar, to taste

Method

1. Preheat the oven to 160C/325F/Gas 3.
2. In a large bowl, beat together the butter and caster sugar, until the mixture turns a lighter colour and is creamy in consistency. This can be done with a wooden spoon, rather than an electric mixer. Beat in the flour, salt, semolina, lemon zest and passion fruit, then use your hands to form a pliable dough.
3. On a floured surface, roll your dough with your hands into a long sausage shape, roughly 5cm/2in in diameter. Wrap in cling film and put in the fridge for about 30 minutes then roll as above.
4. Once chilled, cut 1cm/½in rounds with a sharp knife, trying not to put too much pressure on the dough or you'll end up with a flat edge to the biscuits.
5. Place the rounds on a couple of greased baking sheets and bake in the oven for about 35 minutes, until lightly golden. Lift gently from the tray and sprinkle with caster sugar. Once they're cool enjoy straight away or store in an airtight container.