Brush the bars of the barbie clean to prevent your fish from sticking, then light it and get the coals glowing hot. If your barbie is small, feel free to cut the salmon in half to make it more manageable.
Place the salmon skin side down on a plastic board and, using a sharp knife, slash it evenly all over on the eshy side, making the incisions about 1/2-inch deep. Scatter the lemon zest and most of the chopped fennel tops or basil over the salmon, then push these avorings into the incisions - don't hold back; really push them in! Rub the fish lightly all over with olive oil then season with salt and pepper, giving the skin side a generous amount as most of this will fall off.
When your barbie's ready, lay the salmon on the bars, skin-side down. The esh will start to color from the bottom up and after about 4 minutes the skin should be beautifully golden brown. Carefully ip the salmon over with a roasting fork or a spatula and cook for a further 2 to 3 minutes on the other side. While it's cooking, gently ease the skin away from the fish and put it on the barbie alongside to crisp up.
If your salmon is wild it will have slightly less fat in it, so will be a drier fish. You can therefore cook it for a shorter amount of time, even leaving it slightly undercooked - although this might feel unusual to anyone who nukes fish beyond belief. If it's (organically) farmed, cook it through, but please don't overcook it or it will become too dry. Lift the salmon carefully off the barbecue and place it on a nice serving platter or board. Allow to cool a little, then break the skin into pieces, a bit like poppadums.
Cut the cucumber in half lengthwise, remove and discard the seeds, chop it up and mix it in a bowl with the yogurt. Balance the avors with the lemon juice, half the chopped chile and half the chopped mint or oregano. Drizzle over a little extra-virgin olive oil. Season carefully, to taste, with salt and pepper.
Break the salmon up with a fork into 4 to 6 chunks. Serve with the cucumber yogurt, sprinkled with the rest of the chopped chile and the remaining fennel tops or basil. Drizzle with extra virgin olive oil and make sure everyone gets a piece of the crunchy fish skin.
"Our agreement with the producers of "Jamie at Home" only permit us to make 2 recipes per episode available online. Food Network regrets the inconvenience to our viewers and foodnetwork.com users"
Recipe Excerpted from JAMIE AT HOME by Jamie Oliver. Copyright (c) 2008. Published in the U.S. by Hyperion. All Rights Reserved. Available wherever books are sold. www.jamieoliver.com