Heat up the grill to 450* F
Cut tomatoes into twos and place cut side down on the hot grill
Cook until tender and the skin is charred with juices running out
Place tomatoes on a sheet pan ( lined with parchment if you want easy clean up later) under the broiler in your oven. Cook on one side until tender and the skin is charred with juices running out. Turn and cook on the other side. Usually takes about 10 minutes, but watch them closely
Place tomatoes on a wire mesh directly on the open flames.
Cook on medium flame under tomatoes are tender and charred on all sides and bursting with juice
Once you have roasted the tomatoes, allow to cool for a few minutes. Peel the skin off and finely chop the tomatoes
Mix onions, cilantro, cumin, chili and salt into the tomatoes and then drizzle the oil on top
Chill for an hour before serving