Testing fish for doneness

Using the tip of a paring knife, cut into the flesh of the fish and peer inside. Unless you are cooking fish to the rare stage, the interior should be barely opaque, but still very moist. I also like to use a fingertip to gauge doneness; when ready, the flesh should feel springy when lightly pressed. Halibut, in particular, dries out easily, so be careful not to overcook it.