Put the sourdough discard and melted salted butter in the bowl, mix well. Then add flour, salt and baking soda, use spoon stir to combined. Cover in the room temperature until double in size.

Roll the dough with very thin on the baking mat. Top with salt and oregano. Gently roll to press in spices, cut into one inch squares. The move the baking mat put on the baking tray.

Preheat oven to 175 degrees celsius and bake for 15 minutes, switch sides on baking tray and turn off oven. Let the oven open up a little bit. The heat will make the crackers crispy and not overcooked.