Vegan Khao Soi Recipe
Updated: Oct 30, 2021
Khao Soi (or kao soi) is a curry noodle soup from Northern Thailand and is often recommended as one of the key dishes visitors must try when traveling to Chiang Mai. It is heavily influenced by neighboring China and Myanmar, featuring ginger and soy sauce (China) as well as black cardamom and fresh turmeric (Myanmar). Northern Thai food is the mildest in Thailand which makes this a great dish for kids and those of us who are more spice averse.
This dish lends itself well to veganization because it doesn't rely on fish sauce for seasoning, and instead calls for soy sauce. This is a big help, as the fish sauce in Thai curries is a really tricky ingredient to replace. You can make a swap for a very light soy sauce in a red curry for example, but it will taste quite different from the standard recipe using fish sauce.
This recipe employs a bit of a shortcut. I've developed it using a store bought curry paste, because I think it's a great idea to find new ways to use a red curry paste beyond a simple red curry. The most common size for a tub of Thai curry paste is 14oz, which yields around 50+ servings. So once you've used a paste for a recipe, you'll have to freeze the remaining paste for future use. You can definitely make red curry 50 more times, but wouldn't it be fun to make other dishes with the past in your freezer? In any case, this recipe translates beautifully for vegans, so let's get into it!
Special Ingredients for This Curry
To me, black cardamom smells exactly like BBQ sauce - indistinguishable! For Khao Soi, it's perhaps the most important spice in the recipe. The smoky aroma permeates the dish and sets it apart from any Thai curry you've had before. Needless to say, black cardamom it is essential and unfortunately can't simply be substituted for its green counterpart. Green cardamom lacks a smokey aroma, so it doesn't do the trick on its own. If you twisted my arm, I'd guess you could substitute with a 50% reduced amount of green cardamom plus a drop or 2 of liquid smoke might get you there. But black cardamom isn't impossible to find, so do try to seek it out! I bought mine from Oaktown Spice shop, and have also seen it at 99 Ranch and even on Amazon. The Spruce Eats wrote a lovely comprehensive article on black cardamom, which I highly recommend reading!.
Fresh or dry powder turmeric is another key and somewhat unique ingredient in this curry. The traditional recipe calls for fresh, but I've had a lot of success using dry.
Ginger is quite a unique recipe in a Thai curry. Traditionally the fresh root is pounded into the paste, but I've also had success simmering slices of fresh ginger in the soup to infuse it's flavor and aroma, when I'm doctoring up a store bought paste.