Take fish out of package and rinse salt off with cold water then put fish in bowl of COLD water to cover let sit for 3 hours, changing water every hour.
In blender add eggs and maseca one tbsp at a time till thick(not like paste) and not too runny.When your done dont rinse blender.drain water from fish and pour batter onto fish.
Put tomatoes(quartered), pepper,onion,and garlic in bowl and microwave for 4-5 min till looks cooked. Then put in blender with 3/4c water, sazon,oregano,and bouillon powder.Blend till smooth(will see oregano really good though)
Heat skillet with olive oil, then put one fillet in at a time make sure theirs enough space between them (you might want to make them in batches of three depends how big your pan is).if not enough batter on them you can spoon some on top while cooking, brown slightly on both sides and egg batter will stick dont cook too much because it will fall apart.
Take out the access oil from pan then put potatoes in pan, single layer. Then put fish ontop of them then pour tomatoe mix on top of the fish and cook coverd on low heat for 15min, till potatoes are tender.