Spicy Tomato Soup

1 3/4 pounds ripe tomatoes
2 tablespoons paleo oil
1 teaspoon mustard seeds
1 medium onion, finely chopped
1 teaspoon ground cumin
1/2 teaspoon ground coriander
1/4 teaspoon turmeric
2 dried red chiles
5 1/2 cups water
Kosher salt

Peel and mince the tomatoes. Heat the oil in a medium saucepan. Add the mustard seeds, cover the pan and cook over high heat until the seeds begin to pop. Reduce the heat to moderately low. When the popping stops, add the onion and cook, uncovered, stirring until softened, about 5 minutes. Add the cumin, coriander, turmeric and chiles to the saucepan and cook, stirring, until fragrant, about 1 minute.

Stir in the tomatoes and water; season with salt and bring to a boil. Simmer the soup over moderately low heat for about 30 minutes.

Adapted from: Food & Wine: Inspiration served daily