This whole series of "Burning Questions" posts originated as a somewhat amusing troll through the One Block West Restaurant web site server logs, to see what search phrases were bringing people to the web site. As I went through the logs, the search topics seemed to fall into several broad categories, each dealt with in a separate post in this series. This post deals with fish and shellfish.
What is Set of Shad Roe? The roe (eggs) from the Shad comes in twin lobes called a set. For more, see my post on Shad Roe.
Eating Shad Roe Sashimi Style. You can, but it's not what I would recommend. Shad roe's texture is very soft and less flavorful when raw. I like to roast my roe to medium rare in the oven.
Are Cobia and Wahoo Lean Fish? Yes, Cobia and Wahoo are fairly lean fish, though Cobia can be a little fatter than Wahoo. Because they are so lean, you must take care not to overcook them and they are both best served about medium, still a bit uncooked in the center. Both are typically steakfish, that is they are cut into steaks rather than filets, and both are excellent on the grill.
How Long to Grill Wahoo Steaks/Grilling Wahoo Steaks Wahoo, like almost all steakfish (tuna, marlin, swordfish, cobia, etc.), take extremely well to the grill. They're also very lean fish and do not want to be overcooked. As a very rough rule, fish take about 10 minutes per inch (2.5cm) of thickness to become cooked all the way through. With steakfish, you want them still translucent in the center, so cook them less. I mark steakfish on one side until I see the sides of the steak become opaque, then I flip them and finish them for another couple of minutes. Remember less is more with steakfish and you can always put them back on the grill.
Corvina Same as Grouper. Corvina and Grouper, which is itself a pretty large family of related species, are somewhat closely related but they are not the same. For cooking purposes however, you may treat them identically.
Substitute for Corvina. Corvina is a mild, white, firm fish with small flakes in the Drum family. I serve it at the restaurant in preference to the similar Grouper which is overfished. Any of the larger drums would be fine substitutes: Black Drum, Red Drum, etc. as well as all of the groupers. Striped Bass which we call Rockfish is also a great substitute.
Can You Substitute Clam Juice for Oyster Sauce? Not exactly. Oyster sauce is a thick soy-based sauce. Clam juice is a thin stock akin to fish fumet or fish stock. I'm not sure why you would need to substitute for oyster sauce because it seems to be stocked in most groceries. You could thicken soy sauce with a little corn starch or substitute some other kind of soy product such as bean paste.
Fish Stock Substitute. Easy. Bottled clam juice or steam some mussels and save the liquid.