Be sure to use full-flavoured tomatoes.
Finely grate the zest from one orange, then remove the pith and cut into segments. Peel and segment two other oranges. Peel and cut the remaining orange into rounds (pith on) and then into small triangles.
Place the orange zest, segments and triangles in a bowl with the remaining ingredients. Season to taste and toss gently.
Allow to rest for about 15 minutes before serving.