Chop individually: garlic, scallions, onion, tomatoes and cilantro. Putinto a large bowl. (A large cleaver is very useful for this recipe.)
Grind up cumin seed with a mortar and pestle; add to bowl.
Add canned tomato sauce to bowl.
Cut off stem end of chilies and add to bowl (remove any blackened seeds).
Drain and add diced green chilies to bowl.
Pour whole tomatoes through hands into bowl, “squishing” them between yourfingers as you go.
Add oil, vinegar, salt and white pepper.
Mix thoroughly and adjust to taste.
Keep refrigerated until used.