there are several recipes on the site for fake fishy fun.
One option I like is to replace tuna with some mashed chickpeas for a "tuna" salad. Just make it how you would normally but replace tuna with chickpeas. You can add some kelp powder to get some "fishy" taste to it.
I am also curious on how to mock the taste of fried fish using tofu. I hear if you cook seaweed, it will give the tofu a 'fishy' taste but I have no idea how to cook seaweed, plus isn't it very expensive? Is kelp powder a salt condiment? Will kelp powder mock the 'fishy' taste for all seafood recipes? How much is to be used?
You can make a pretty decent battered and fried "fish" using tofu and nori, which is a type of seaweed and comes in dried sheets in various sizes. Look for it in Asian sections, particularly in the sushi section of your grocer.
Freeze the brick of tofu overnight. Thaw it. Press out as much water as possible. Slice it into portions. Pour on a little soy sauce, let it soak in. Cut out pieces of the nori sheet that are the same size as your tofu portions. Press one on to each tofu portion. The moisture from the soy sauce will moisten the nori so it will become softer and pliable.
Make a batter using flour and water. Add water a little at a time to get the consistency you want. The texture of the batter should resemble cake batter, or a little thinner. Dip each nori-covered tofu portion in the batter, letting the excess drip off.
If you have a deep fryer, the oil should be at least 350 or 375 degrees F. Test it with a blob of batter first. The batter blob should turn golden brown in only a few minutes.
Plop in your battered tofu pieces into the hot oil. Stirring occasionally to make sure they're not sticking to the sides or bottom of the fryer. The batter should be golden brown in a few minutes.
Take them out, place them on a wire rack that has paper towels underneath it.
I only make this every once and a while, because it's really fatty and takes a bit of preparation to make. But it's yummy. I like to dip them in ketchup, or vinegar.
Hope this helps, and wasn't too complicated of an explanation.