Finely dice the tomatoes. Toss with salt and leave to drain in a sieve for about 10 minutes.
Halve the cucumber, then scrape out and discard the seeds.
Finely dice the rest.
Finely dice the red onion - the smaller the better.
When ready to serve, toss everything together with a good squeeze of lime juice.
«You could add some herbs to the recipe - mint or coriander would be perfect»