1 Preheat your oven to 160C/Gas Mark 2.
2 If you’re not using the matcha powder, using a pestle and mortar, grind the Earl Grey tea until it forms a very fine powder.
3 Sieve the flour and the ground tea together.
4 Mix together the butter, sugar and salt in a bowl and then add the remaining ingredients. This should form a dough which easily comes away from the mixing bowl.
5 Shape the mixture so it resembles a brick structure and refrigerate for 10-15 minutes.
6 Roll the shortbread out to 1.5cm (½ inch) thickness and place on to a baking tray lined with greaseproof paper.
Bake for 10-15 minutes until the shortbread is starting to turn golden brown, then remove from the oven and sprinkle with caster sugar.
7 Cut the shortbread in to the desired shapes (this might be fingers, rounds or squares), while still hot, then leave to cool.
You can dip the shortbread in tempered milk chocolate or enjoy it plain.
Store in an airtight container until needed.