Batter the "fish" and place on a cookie sheet that has been lined with parchment paper.
Bake for 20 minutes.
For Gluten-Free "Fish"
Most all-purpose gluten-free flour mixes work well.
I find that they need slightly less water than traditional flour, so add about 1/2 cup of water and then slowly add more until you get a pancake-like batter.
If you want a gluten-free vegan sandwich bun, I find that the Schar brand works well.