Punch the crackers, nuts, butter and oregano into a crumb in the bowl of a blender.
Place the crumb in the mold and tamp it tightly. Send the form to the refrigerator.
PS If you want the base to be more dense and not crumble, then bake it in the oven at 180"C for 8-10 minutes. Cool and continue assembling. I like a looser and more airy base, so I just send the mold with the base to the refrigerator.