Add the rice to a bowl or container and completely cover it in warm water (110° to 115°) and soak for about 10 minutes. Rinse under cold water and set aside to dry in a strainer.
While the rice is soaking, add 1 tablespoon of oil to a large frying pan and roast the tomato, onion, and garlic over medium-high heat and sear on all sides until blistered and browned, which takes about 10 minutes total.
Transfer the roasted vegetables to a blender and puree until smooth. Set aside.
Add 2 tablespoons of oil to a frying pan over medium heat and fry the rinsed and dried rice for about 5 to 6 minutes while continuously stirring.
Pour in the pureed tomato mixture and stir to combine and cook over medium heat just until the rice has absorbed most of it, which takes about 5 minutes.
Add in the chicken stock, salt, serrano pepper, cover with a lid, and cook on low heat for about 10 minutes or until the liquid has been absorbed.
Remove the serrano pepper, break up the rice using a fork and serve.
Notes
Make-Ahead: You can make this recipe up to 1 hour ahead of time. Keep warm covered over very low heat until ready to serve.How to Store: Cover and store in the refrigerator for 4 to 5 days. You can freeze this covered for up to 3 months. Thaw in the refrigerator for 1 day before reheating.How to Reheat: To reheat, add the desired amount of rice with 2 to 3 tablespoons of chicken, or water, and heat over low to medium heat while occasionally stirring until hot.I prefer to remove the seeds from the pepper because I have a low tolerance for spice, however, you can leave the pepper whole or even with just a few seeds if you like spice.