Begin by gathering all your ingredients. Make sure your jasmine rice is cooked and cooled, as day-old rice works best for fried rice dishes.
In a wok or large skillet, heat the coconut oil over medium-high heat. Allow it to melt and coat the pan, creating a rich base for your dish.
Add the diced onion and sauté for about 2-3 minutes until it turns translucent. Then, toss in the sliced scallion and minced ginger, stirring for another minute to release their flavors.
Stir in the sliced shiitake mushrooms and diced tomatoes. Cook until the mushrooms are tender and the tomatoes start to break down, about 3-5 minutes.
Add the cooked jasmine rice to the pan, breaking up any clumps as you stir. Ensure the rice is evenly coated with the aromatic mixture.
Pour in the soy sauce, granulated sugar, Thai chili paste, and squeeze in the lime juice. Toss everything together to combine. The sugar will help balance the flavors.
Toss in the kaffir lime leaves, lemongrass, and Thai red chili flakes. Mix well, allowing the herbs to infuse their flavors into the rice.
Taste the fried rice and season with salt and black pepper as needed. Remember, the soy sauce already adds saltiness, so adjust accordingly.
Remove the pan from heat and fold in the freshly chopped cilantro. Serve your Tom Yum Fried Rice hot, garnished with additional scallions and lime wedges if desired.