Trim the swordfish of any fatty layers and cut out any bloodstained flesh or ask your fishmonger to do this for you.
Cut into 4 chunky steaks (about 2cm thick). The thickness must be even for a perfect 'cuisson' (a chefs term for 'doneness').
In a shallow dish, mix 120ml oil, 1 tbsp sesame oil, juice of 1 lime, 1 lightly crushed garlic clove, 2 good pinches of salt and the rosemary.
Put the fish steaks into the marinade, cover and chill from 1 hr to a day until ready to cook, turning them once or twice.
For the salsa, peel and dice the pineapple and put two thirds of the diced flesh into a blender or food processor with 1 tsp salt, the shallot, 2 tbsp olive oil and the remaining sesame oil. Whizz until smooth.
Slit the chillies open and remove seeds. Chop the flesh. Peel the lemongrass; cut the stalk into strips then dice.
Place the chillies, lemongrass, 1 garlic clove and lime juice into a large mortar. Roughly crush, then work the onions and ginger in to form a paste.
Finely chop the coriander leaves and shred the basil leaves.
Add to the chilli mixture, then mix with the pineapple pure and the extra pineapple dice. Put in a bowl and pour over the remaining 1 tbsp oil. Cover and chill for up to a day.
To cook the swordfish, heat a grill or griddle pan until really hot.
Drain the steaks from the marinade and place on the griddle. Watch the flesh change from translucent to pale cream the cuisson 1 min. Turn the steaks and cook for 1 more min no more! To serve, arrange the cherry tomatoes, cucumber pappardelle and roasted lettuce on plates.
Drizzle over the salsa and top with the swordfish.
