Pour the water into a pot and bring to a boil. Add the shallots, galangal, lemongrass, and kaffir lime leaves. Boil until fragrant.

While waiting for the water to boil, wash the chicken drumsticks thoroughly and cut them into bite-sized pieces. Place them in a bowl. Once the water is boiling, add the chicken pieces to the pot. Add the chicken blood tofu and oyster mushrooms. Reduce the heat and simmer for 15 minutes. Then add the culantro and cilantro. Turn off the heat and transfer to a serving bowl.

Lightly smash the red chili peppers and add them to the Tom Yum. Season with lime juice, fish sauce, and RosDee seasoning powder. Serve immediately.

For the best Tom Yum flavor, season each bowl individually instead of seasoning the whole pot. Adding lime juice directly to the pot can make it bitter. This way, you'll get restaurant-quality Tom Yum. If you like it spicier, add more chili peppers.