陆 lemon, juice only
1 lemon, zest only
1 tsp lemon juice
225g/8oz plain flour
55g/2oz light muscovado sugar
a little caster sugar
陆 tsp ground cinnamon
115g/4oz currants
录 tsp ground ginger
录 tsp freshly grated nutmeg
30g/1oz mixed chopped peel
陆 tsp salt
3 tbsp Pedro Xim茅nez sherry
200g/7oz chilled butter, cubed
knob of unsalted butter
1 free-range egg white