Heat a nonstick skillet, wok, or pot over medium-low heat and add the oil. Once the oil is hot, add the pounded mixture and fry until fragrant, about 2 minutes.
10 tablespoons neutral oil
Food processor method
Transfer all the herbs and spices to a food processor. Blend until a bright red paste forms.
Heat the oil in a skillet over medium heat. Add the paste and fry until fragrant, about 2 minutes.
Notes
Tom Yum paste will keep for 1 week in the refrigerator or 6 months in the freezer. Tip: freeze it in ice cube trays so you can easily portion out small amounts.