The flame-resistant clay pot we tested this recipe with was 8 inches in diameter and 3 inches deep. Check the manufacturer’s instructions for how to season your clay pot. The best way to clean a clay pot is to gently scrub it with warm soapy water, rinse it and then air-dry it overnight. The sauce in this recipe gets some of its richness from chu hou paste, a sweet fermented soybean condiment that famously adds depth of flavor to braised dishes. We also bolstered the sauce with vegetable umami seasoning, an excellent vegan substitute for fish sauce; we tested the recipe with and without the umami seasoning and enjoyed the savory notes it added. However, you can use regular fish sauce (and regular oyster sauce) instead.