Whether you use it for cooking meals or for spell making; a large cauldron was needed to sustain. Round and dirty it serves its purpose as intended. Are you a witch or a cook? Or are you a witchy cook? Using a recipe? Creating as you go? Put what you wish, add whatever feels right, stir, stir, stir some more, voila, the magic concoction you brewed within is done. Enjoy the consequences!