- Box of good quality chicken stock – about 4 cups
- Coconut milk – 1 cup/can
- A few stalks of lemongrass
- Galangal – fresh – 20 1/4″ slices – be careful cutting!
- Garlic -two or three cloves – I crush with a garlic press but you can chop it up fine
- Nam Prik Pao, Chili Paste, or Curry paste -a tablespoon or two (optional and not traditional)
- Kaffir Lime Leaves – about 10
- Chopped green onion – white part small, green part longer chunks
- Thai chilis – For about 3 stars I cut a few in half lengthwise and seed, and then about 3 chopped with seeds.
- Fish sauce – about 1 tbsp (The saltiness can vary a lot across brands, so start with less always.)
- A lime, maybe two.
- Palm Sugar – 1 tbsp. Also fine to use regular sugar
- Cilantro leaves – I chop a standard bunch and use most of it
- Several cups of mushrooms – whatever you like, or a mix. Never Shitaki
- Tom Kah Gai: One to two large chicken breasts chopped into thin strips
- Tom Kha Goong: Prawns
- Tom Kha Talay: Mixed seafood
- Or just make it veggie
To prepare the lemongrass, use only the bottom white part (about 6 inches) and discard the woody grass part of it including the outside of the 6-inch part. Cut it in half lengthwise. With the flat side of a cleaver or a heavy object, pound the lemongrass so it releases the flavor. Also slice the galangal. Sometimes I use a food processor for that – it’s hard and easy to cut yourself.
Put the chicken stock into a pot and bring to a boil. Add the galangal, lemongrass, half the sugar, about 1 tsp of the fish sauce, and lime leaves. Simmer for 5 minutes or a longer as you prepare the rest. I often leave it for about half an hour. For a richer taste, you can add some extra chicken stock and then boil longer to let it reduce down. I also chop up the cillantro here and add the finely chopped stem parts to this.
In a frying pan, heat a little oil and fry the chilies, garlic, curry paste (optional), and scallion, and simmer for another 5 minutes. Don’t burn it, just heat it. The curry paste is not traditional but it makes it a little richer in taste and color. Add the fat (solid) part of the coconut milk spoon by spoon and Simmer until hot.
At this point I often remove at least most of the galangal and lemongrass from the liquid. It’s traditional to leave it in but it gets annoying picking out the inedible bits. I also squeeze the juice from the galangal with a lime press. Add the paste to the soup.
Once I added the coconut milk to the soup itself and it never combined – the fats floated on top like separated cream. I think it needs to get hot and mixed with other solids to form an emulsion before being mixed with the rest of the liquid.
Once that’s all hot, slowly add the rest of the coconut milk making sure it stays hot (and doesn’t separate). Add the meat/seafood and mushrooms and boil until just cooked. If I’m adding clams I do that here too. When you see chicken turning all white on the outside, it’s 90% done. If in doubt, slice your thickest piece. Make sure it boils before you taste it. Add more of the cillantro leaves. Then turn the heat way down and squeeze in the juice of a lime or two.
Let it simmer for at least 5 minutes, and then it’s taste test time. You still have leftover sugar, fish sauce, and limes. Those are the three you have to adjust carefully. It probably needs a little saltiness/richness so add a bit more fish sauce and retest. If you make it with seafood it will need less. Be careful with the fish sauce but also don’t be afraid – it’s key.Test for saltiness and sourness. You should get the earthy flavor of galangal, Some saltiness/fishness, sweetness from the coconut milk, and a fair bit of lime flavor, and some chilli in the background. I generally add a second or third lime here too. Keep sugar mainly for if you add too much lime or fish sauce – it’ll counteract/disguise either to some extent. Otherwise you don’t need it. You can try squeezing more juice from the galangal if it’s needed. And also add more chilis to make it spicier. Or chili paste if you want.
Serve and top with cilantro leaves. I serve with lots of rice so it’s almost a sauce.