2 plum tomatoes (6 oz)
3 Tbs extra-virgin olive oil
1/2 tsp cumin seeds
2 tsp crumbled dried red chilies
3/4 c coarsely chopped yellow onion (1 med/ onion)
2 Tbs coarsely chopped garlic (about 2 large cloves)
1 Tbs coarsely chopped fresh ginger
3/4 tsp coarse salt
2 Tbs coarsely chopped cilantro
1/2 tsp rice vinegar
Bring a saucepan of water to a boil. Add tomatoes, and cook until soft, about 5 minutes. Drain and let cool slightly. Squeeze juice and seeds from tomatoes over a small bowl, and reserve. Coarsely chop tomato flesh.
Heat oil in a skillet over med-high heat. Add cumin and chilies and cook until chilies darken and become fragrant, about one minute. Add onion, garlic. and ginger and cook until golden brown, about 3 minutes. Reduce heat to medium and cook for 2 minutes. Add chopped tomatoes and salt and cool another two minutes. Stir in reserved tomato juice and seeds and cook until almost all of the liquid has evaporated about two minutes. Remove from heat and let cool slightly.
Puree mixture with the cilantro in a food processor until smooth. Add rice vinegar and more salt if desired.
Sauce can be refrigerated in an airtight container for up to two weeks, bring to room temp before serving.