This is one of those typical case of “you should avoid hotel restaurants” that turned out to be true. If you see this, keep walking.
A small very busy sushi restaurant, just North-East of the tourist filled Astronomical Clock. It's definitely recommended if you're wanting something different from the local fare and isn't too far out of the way.
A bar and family restaurant that serves Prague local fare. This had the best potato dumplings from my whole trip. Food came out slow but fresh and service was friendly.