Equipment
* optional
Ingredients
Aromatics
- 50 g galangal, sliced into thin rounds
- 2 lemongrass stalks, smashed and cut into 5cm pieces
- 5 makrut lime leaves, bruised and torn
- 3 bird's eye chilies, bruised
Liquids
- 400 ml chicken broth, low sodium preferred
- 400 ml full-fat coconut milk, unsweetened, shaken well
Protein and Vegetables
- 300 g boneless skinless chicken thighs, sliced into bite-sized strips
- 150 g oyster mushrooms, torn or sliced
Seasoning and Garnish
- 45 ml fish sauce, premium quality
- 45 ml fresh lime juice, freshly squeezed
- 15 g palm sugar, finely chopped
- 10 g fresh cilantro, roughly chopped, leaves and tender stems
- 15 g chili oil
Nutrition (per serving)
Method
Prepare your aromatics by slicing the galangal, bruising the lemongrass with the back of your chef's knife, tearing the makrut lime leaves to release their oils, and lightly crushing the bird's eye chilies. Prepare the raw chicken on a separate meat cutting board to avoid cross-contamination.
In a medium pot, bring the chicken broth to a gentle simmer. Add the prepared galangal, lemongrass, makrut lime leaves, and bird's eye chilies. Let this infuse over medium-low heat for 10 minutes.
Pour the coconut milk into the infused broth. Stir well and bring back to a very gentle simmer. Do not let the soup come to a rapid boil, as this can cause the coconut milk to split and become grainy.
Add the sliced chicken thighs and oyster mushrooms to the gently simmering liquid. Poach until the chicken is completely cooked through and reaches an internal temperature of 74C or 165F, about 5 to 7 minutes.
Remove the pot completely from the heat source. Stir in the fish sauce, freshly squeezed lime juice, and palm sugar. Stir until the sugar is fully dissolved. Taste the broth and adjust the balance; it should be equally sour, salty, and creamy, with a subtle sweetness and a kick of heat.
Ladle the hot soup into bowls. Garnish generously with fresh cilantro and an optional drizzle of chili oil. Serve immediately, instructing guests to leave the tough galangal, lemongrass, and lime leaves in the bowl as they are for flavor infusion only.
Chef's Notes
- Galangal is not interchangeable with ginger. While they look similar, galangal has a sharp, piney, and citrusy flavor profile that is non-negotiable for authentic Tom Kha.
- Do not attempt to eat the aromatics. The lemongrass, galangal, and makrut lime leaves are traditionally left in the bowl for aesthetic appeal and continued flavor release, but they are too woody to digest.
- Adding lime juice off the heat is a critical culinary technique in Thai cooking to preserve the bright, fresh notes of the citrus and prevent dairy or coconut milk from splitting.
- For the best mouthfeel, look for a coconut milk brand that contains at least 60 percent coconut extract. Shake the can vigorously before opening to incorporate the fat cap.
Storage
Refrigerator: 3 days — Store in an airtight container. Reheat very gently to prevent the coconut milk from separating.
Freezer: 1 month — Freezing may cause the coconut milk to separate upon thawing. Texture will change slightly but flavor remains intact.
Reheating: Warm gently over medium-low heat on the stove, stirring frequently. Do not bring to a rolling boil.
