Terra Cotta Cazuela Dishes This exceptionally sturdy clay cookware is safe to use in the oven, on the stovetop, or in a microwave. They are the product of a unique refractory clay method used since antiquity that produces a cazuela that is close to a brick in density. Because of this classic process, unique in our time, dishes served on the table, such as bacalao a la pil pil , will continue to simmer for another 5 - 10 minutes.