Place the tomatoes and the onion in a food processor and puree until completely smooth. Measure out 2 cups of the mixture and set aside (reserve any extra for another use or discard).
In a large Dutch oven, heat the oil over medium-high heat. Add the rice and cook, stirring constantly, until the rice is lightly toasted, 8 to 10 minutes. Reduce the heat to medium-low and add the jalapeño peppers, cooking until they are softened, about 2 minutes. Stir in the garlic and the tomato paste and stir to coat the rice, about 30 seconds.
Stir in the tomato mixture, chicken stock, salt and cumin. Increase the heat to medium-high and bring to a boil. Reduce the heat to low and cook, covered, until all of the liquid is absorbed and the rice has finished cooking, about 15 minutes. Remove the rice from the heat and stir. Re-cover the pot and allow to sit for 10 minutes. Gently stir in the lime juice and cilantro and serve.