BBC says: "A white-fleshed sea fish found in European waters, John Dory (also known as St Peter's fish), is an odd-looking creature with an oval, flat body and a large, spiny head. The white, boneless, meaty flesh is firm and flavoursome and can be cooked in a variety of ways: grill, sauté or poach it. It’s popular with chefs because it goes well with a wide variety of ingredients and flavourings and the bones from its head make an excellent stock."
"John Dory is an odd-looking fish with long spines and a large dot on its side, and its bones are excellent for making fish stock.
John Dory is sometimes referred to as St. Peter fish (or versions of that in Italian or French) because of a legend that the black spot on its side represents St. Peter's fingerprints.
John Dory is best prepared with its skin on. While it is considered a delicacy, and can command a high price in fine-dining restaurants, it also is often used for making that most prosaic of dishes — fish and chips."
Yes, it's certainly an odd-looking thing, and while I've got a whole one, every recipe I can find talks about fillets. I learnt how to fillet a fish on the cookery course, but this.... hmm. I have found a site that admits it's a bit tricky, and gives me a video of how to go about "butchering" a John Dorey. Equipment needed - decent pair of shears. My kitchen scissors are either too small or too blunt. I forsee shopping in the near future.