Serving a side dish with salt-baked fish makes sense for a couple of reasons. First, it's a great way to round out a meal. Second, it gives you some texture diversity and an opportunity to play around with complementary flavors and ingredients. Finally, if you get your fish on point, you don't have to worry about it being undercooked or over-salted—a side dish can always save the day if something goes wrong (or if you just want more to eat).