Take the seeds out of the tomatoes and green peppers, and dice them so they are all the same size. Cut the onions into quarters, then into very thin slices. Salt it all.
Cut the mint into tiny pieces, add this to the mix, then add the lemon juice. Mix it all up.
Put this mix in the middle of a large serving plate or platter. Garnish the plate with lettuce leaves, arranged nicely around the edge of the plate. Garnish also with hard boiled egg, and radish. Slice the tomato at the end of the recipe, and arrange the slices around the edge of the plate, or quarter them, and similarly arrange them.
Arrange the tuna on top of the vegetables in the center of the plate. Add the feta and scatter the olives around the plate. Drizzle the whole dish with olive oil.