This salad is very popular all over North Africa, particularly in Tunisia. It is not unlike the French salade niçoise, so its origin might just as well be Nice as Tunis.
If you wish to skin the tomatoes, plunge them in boiling water for a minute or two first. Halve the sweet peppers and grill them skin side up until they are soft and mellow. Skin and seed them. Chop the onions and the chilli pepper finely. Slice off one end of the tomatoes, scoop out the seeds and juice, and slice them. Cut the sweet peppers into narrow ribbons.
Put all the vegetables i