One side seared tuna salad with green mango and sweet Nahm Jim

Tuna seared on one side only, the other left raw, sliced over shredded green mango with a sweet nam jim of palm sugar, lime, fish sauce and chilli. Kaffir lime leaves run through the dressing. Thai salad cooking at its most disciplined.

Nam jim wan (sweet nam jim) is one of the four canonical Thai dressings, the lighter, sweeter cousin to nam jim jaew (the smoky, isaan-style chilli sauce). Built on palm sugar dissolved into lime juice and fish sauce, with chilli, garlic, shallot and ginger blitzed in for body. The kaffir lime leaves go in finely chopped at the end; they shouldn't dominate the sauce, just perfume it.

Green mango is the unripe Thai-variety mango, firm, white-fleshed and tart. Shred it thin on a mandolin or a julienne peeler so the strands take the dressing without going limp. The crunch is structural; the tartness is the foil to the rich, fatty tuna.

Searing the tuna on one side only is the Vietnamese-French move that lets you show both the cooked surface and the raw centre. Get the pan smoking hot, sear for thirty seconds, plunge into ice water to stop the carry-over cook. Slice paper-thin across the grain. Scatter coriander and Thai basil over the top; the salad eats fresh and bright, sharp enough to wake up a heavy table.