1. To make the anchovy butter, place butter and anchovies in a food processor and purée. Add lemon juice and pepper and process for 1 minute. Roll the mixture into a log with a sheet of baking paper or foil (about 35cm long and 4cm in diameter). Wrap in cling wrap and refrigerate until firm. Slice into 1cm rounds. (This will make about 35 portions. Keep the rest in the freezer to use to add flavour to all sorts of dishes.)

2. Preheat the barbecue to a high heat. Make sure the grill bars are well cleaned. Place the salmon fillet on a chopping board, skin side up, and scrape the skin with the back of a knife to remove excess moisture. Repeat 3 times and dry with kitchen paper.

3. Season the salmon fillets with sea salt and brush with extra virgin olive oil. Place the fish on the grill with the skin side down and cook for 3 minutes, then turn over and cook for a further 3 minutes. Remove from the grill and place a 1cm slice of anchovy butter on each piece of fish. Set aside, keeping warm until ready to serve.

4. For the spinach, heat the extra virgin olive oil in a sauté pan and add the garlic. Cook over medium heat until the garlic is light brown. Add the spinach in about three batches, pushing it around with a pair of tongs. Turn the heat up high and add some sea salt and the chilli and continue to stir. The spinach should become glossy and wilted as it is coated with the oil. Squeeze over lemon juice and a good grind of fresh pepper.

5. Divide the spinach between four large white plates, then place a piece of fish on top of the spinach and squeeze lime juice over each. Garnish with a good grind of pepper and serve immediately.