Rick Moonen's Hoisin Glaze.
Mix first 5 ingredients together. Taste and season with salt. Brush it on after your fish is cooked. Can be halved.
And finally one thing I wanted to say is that I really recommend Kikkoman's Hoisin sauce. I read somewhere, (it probably the Cook's Illustrated people,) that, after taste-testing, it was the best one. So I gave it a try. And I really do find it more delicious than the others. However, I was never unhappy with the other brands I tried either. So use what you can find.