Mix the lavender with the sugar then lightly cream it with the butter. Sieve the flour and the salt into the butter and sugar mixture.
Mix together to make a soft dough. Place in the fridge to chill for 1 hour.
Roll the dough out to approximately 5mm thick. Cut into shapes using 8cm cutters. Place on a baking sheet and sprinkle with a little caster sugar.. Bake for 15/20 minutes or until a pale gold colour. The shortbread will become crisp on cooling.