This is really simple. First of all give your fish a wash, then with a sharp knife score across each fish down to the bone at 2.5cm/1 inch intervals on both sides. This allows flavour to penetrate the fish and lets the fish’s juices come out.
Preheat the oven to 200ºC/400ºF/gas 6. Get yourself a bowl and add the tomatoes, garlic, oregano or basil, spring onions, balsamic vinegar, a pinch of salt and pepper and the zest and juice of 1 lemon to it. Loosen with a couple of good tablespoons of extra virgin olive oil and mix well, then spread over the bottom of a large roasting tray. Use one that will fit all 4 fish quite snugly (or you can use two smaller trays). Place the fish on top – top to tail.
Now add the olives, parsley, juice and zest of the second lemon to the bowl that the tomatoes were in. Loosen with a little olive oil and then divide this mixture between the fish, placing an equal amount on the centre of each. Cook in the preheated oven for 12 to 15 minutes, depending on the size of the fish. To check whether they’re done, take the tip of a knife and push it into the thickest part of the fish. When done, the flesh will easily pull away from the bone.
Once cooked, remove the fish from the oven and allow them to rest for 3 or 4 minutes while you get your guests round the table, serve them some wine and dress your salad. Then you can come back to the fish. Divide them up at the table on to 4 plates, making sure that everyone gets some tomatoes and juice spooned over the top of the fish. Lovely!
• from Jamie's Dinners