Preheat the oven to full whack. Get yourself a large roasting tray that your whole salmon will fit inside – you’ll probably need to lay the fish diagonally across the tray, like I’ve done in the picture –it won’t matter if the head and tail drape over the sides a little. Scrub the potatoes clean, then slice into ½ cm rounds. Lay them over the base of the tray and season well with sea salt and black pepper. Cut the fennel into six wedges, scatter over the potatoes and give it all a generous drizzle of olive oil. Pick half the herb leaves onto a chopping board, .finely grate over the lemon zest, then roughly chop everything together. Scrape this mixture into a bowl. Using a sharp knife, make 6 slashes on each side of the fish, about 2cm deep and at an angle. Sprinkle salt and pepper into each incision, stuff each with a pinch of the lemon-herb mix, then smooth flat. Drizzle the fish lightly with olive oil, then lay on top of the potatoes and fennel. Slice up one of the lemons, then stuff into the cavity with the remaining herbs. Bake the fish in the screaming hot oven for 15 minutes, then turn the temperature down to 180ºC/350ºF/gas 4 and cook for a further 30 minutes. To check if the fish is cooked, take a clean skewer and push it into the deepest part of the fish, just behind the head. Count to 10, then carefully take the skewer out and hold it against your top lip –if it’s nice and warm, the fish is cooked. Squeeze the juice from the remaining lemon over the top, drizzle with a little extra virgin olive oil.. Delicious served with a bowl of steamed seasonal greens.