Preheat the oven to 110 ºC

Cover a baking tray with baking paper and lightly grease the surface with oil.

Grind the lavender flowers in a mortar.

Beat the egg whites with the salt until stiff. Add the lavender and cardamom and beat until well mixed. Add the sugar bit by bit until it's all mixed in well and keep beating for another few minutes.

Make small heaps on the baking tray using two spoons and bake for 90 minutes in the oven (give or take 30 minutes).