Heat a tablespoon of olive oil in a saute pan over medium heat until lightly smoking, add the onion and saute until caramelized, about 10 minutes. Place your tomatoes on the bbq and proceed to blacken them. Put the garlic, peppers, and onion into a tinfoil wrap, with 1 tbs of oil and lay it on the bbq to get hot. Transfer the onion, half the blackened tomatoes (be sure to core the tomatoes), and garlic/pepper combo to a food processor or blender, and pulse until finely chopped but not pureed. Add the cilantro and pulse again to mix. Fold in the rest of the tomatoes and add the remaining oil, vinegar, salt, and sugar. This salsa served while still hot will not last very long, so get a taste before you turn the bowl loose! Bon appetite.