I recently went looking for recipes for one person and came across a couple of books:
Cooking for One by America’s Test Kitchen
Easy One Bowl Baking by Kelli Marks
The Utlimate Baking For One Cookbook by Kelly Jaggers (I’ve only read this last book which doesn’t have fish recipes in it I don’t think)

Actually this was pretty helpful. I can’t eat much food so I’m constantly looking for ways to cook a single thing very well.