My wife and I had a tasty and pleasurable dinner at De Korenmarkt.
I had fish soup, which was very good, and a huge pot of fresh mussels. My wife had an excellent tomato soup, and prawns with noodles. The prawns were unpeeled, which was a little annoying, but very tasty.
Service was friendly.
Hoorn is clearly a place where tourist traps abound, so this is definitely a good find and worth a visit.