What is "monkfish"? A trend or trendy?
Digging into my copy of the
Food Lover's Companion, by Sharon Tyler Herbst (which was published in 1990 and has over 3000 entries, compared to the 4th edition which was published just last year and has over 6000 entries, which is why I've got the new edition on my Jessica's Biscuit wishlist)...
Monkfish is a subset of angler fish. Anglers bury themselves in the sea floor sediment and twich long filaments that grow from their heads. Since the filament resembles a worm, other fish and shellfish are attracted to the filament and quickly find themselves "engulfed" by the angler's huge maw.
Anglers are very ugly, but are low in fat (who wouldn't be, just slobbing around on the sea floor like that) and firm-textured. Their flavor is mild and sweet, comparable to that of lobster. Unfortunately, the only part of anglers that is considered edible is the tail, but that can be prepared by almost any method suitable for fish.
So, are anglers (and therefor monkfish) trendy? No. They don't go out much, and when they do show up at a bar or club the beautiful people quickly shy away. Their only companions tend to be accountants - otherwise, they just sit around like so much fish.
Sorry, couldn't resist.
Monkfish, as an ingredient, shows up as part of various traditional bistro dishes, such as bouillabaisse or bourride, neither of which the trendy people can pronounce. I would put bistro cooking as trend, not trendy - it is a range of cooking that has been around a long time and is being rediscovered by serious cooks. If you find someone offering monkfish as something new and trendy, like they've just discovered it, take them aside and give them a good bitchslapping. They'll have deserved it.