Cut the tuna fillet into very fine slices using a sharp knife.
Cut the avocado in half and then use the knife to stab the pit (seed) with a sharp blow and remove.
Extract the avocado pulp with a spoon. Place the pulp in the blender beaker, add the lime juice, vegetable oil and a pinch of salt. Blend to a smooth even cream and transfer to a squeezy applicator bottle with a narrow nozzle.
Arrange the tuna slices on a plate, with an eye to form and proportions. The resulting shape should be rectangular.
Dress the tuna carpaccio with a drizzle of oil and the Maldon salt. Garnish with the herbs, chilli pepper and avocado mayonnaise.
