Preheat oven to 200 C. Brush corncobs with a little olive oil and place on a baking sheet. Roast in the preheated oven at 200 C for fifteen to twenty minutes or till corn kernels turn a light golden brown. Alternatively, place corncobs directly on grill or flame (need not brush with olive oil) and roast till some of the kernels turn black from the grilling process.
Turn over frequently while roasting. Let corncobs cool and remove kernels. In a medium sized bowl, combine corn and all the ingredients (this salsa can be made one day ahead).
Cover and refrigerate. Bring to room temperature before using.