Put sourdough starter into the mix bowl. Then add melted butter and milk.

Add egg yolk, sugar and fresh makrut thai lime leaves. Whisk until mix it well.

Transfer the mixture into the tray, greased and lined with parchment paper. Use spatula spread it evenly. Bake at 160 degrees celsius for 20 minutes or until dry and crispy. Remove off the oven, let it cool down break for keep it in the container.