Ingredients

2 plum tomatoes (6 ounces) 

3 tablespoons extra-virgin olive oil 

1/2 teaspoon cumin seeds 

2 to 3 teaspoons crumbled dried red chiles 

3/4 cup coarsely chopped yellow onion (1 medium onion) 

2 tablespoons coarsely chopped garlic (about 2 large cloves) 

1 tablespoon coarsely chopped fresh ginger 

3/4 teaspoon coarse salt 

2 tablespoons coarsely chopped fresh cilantro 

1/2 teaspoon rice vinegar 

Preparation

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 medium-high heat. Add cumin and chiles, and cook until chiles darken and become fragrant, about 1 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 cook for 2 minutes. Stir in reserved tomato juice and seeds, and cook until almost all of the liquid has evaporated, about 2 minutes. Remove from heat, and let cool slightly.

Puree mixture with the cilantro in a food processor until smooth. Add vinegar and more salt if desired. Sauce can be refrigerated in an airtight container for up to 2 weeks; bring to room temperature before serving.