These ttukbaegi bowls are shiny but if I can find them I prefer the ones that aren’t shiny. They can be used to cook many dishes including sundubu, doenjang-jjigae, and samgyetang. They’re perfect for stews and soupls because the stone retains the heat until you finish your meal.
If you can’t find these bowls, you can cook Korean food without them, but they are very suitable for Korean cuisine and it’s worth trying to find them. In Korean grocery stores they should be less than $10 and as low as $4.