In a bowl, combine the rinsed rice with enough cold water to cover by 1 inch. Let soak for 15 minutes. Drain the rice well.
In a liquid measuring cup, combine the 1 1/4 cups water and the tomato paste and whisk until dissolved. Set aside.
In a large saucepan over medium heat, combine the oil, cumin, coriander, mustard seeds, chiles, garlic and ginger. Cook until the seeds begin to pop and the mixture is fragrant, approximately 1 minute.
Stir the rice and salt and cook, stirring, until coated with oil, about 30 seconds. Stir in the water-tomato paste mixture and bring to a simmer. Cover, reduce heat to low and cook until the water has been absorbed, about 15 minutes. Remove from the heat, add the tomatoes and let sit, covered, for 5 minutes. Stir in the cilantro, fluffing the rice with a fork. Garnish with fried shallots.