Brush the bars of the barbie clean to prevent your fish 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 fleshy side, making the incisions about 1cm deep.
Grate the lemon zest and most of the chopped fennel tops or basil over the salmon, then push these flavourings 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 flesh will start to colour from the bottom up and after about 4 minutes the skin should be beautifully golden brown.
Carefully flip 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 us Brits, who nuke fish beyond belief, this is a really good idea!
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 poppadoms.
Cut the cucumber in half lengthways, remove and discard the seeds, chop it up and mix it in a bowl with the yoghurt. Balance the flavours with the lemon juice, half the chopped chilli, 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 four to six chunks. Serve with the cucumber yoghurt, sprinkled with the rest of the chopped chilli 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.