Instructions

1. In a blender or food processor, combine the onion, tomatoes, tomato paste, and garlic. Blend until smooth. (Do this in batches if necessary.)
2. Transfer to a saucepan and stir in the cumin, paprika, onion powder, garlic powder, oregano, a generous pinch of salt, and 3 cups water. Bring to a boil over medium heat and cook for 10 to 15 minutes.
3. Meanwhile, in a small bowl, mix the arrowroot powder with 1 tablespoon water, stirring well to avoid any lumps. Add this to the sauce, stirring well.
4. Simmer, covered, for 15 to 20 minutes, until the sauce reduces a bit and is fragrant. Taste and adjust the seasoning.
5. Store in an airtight container in the refrigerator for up to 7 days.