Khao Soi: Thai Curry Noodle Soup

Regional Thai food isn't very well known, but khao soi ข้าวซอย, with egg noodles in an aromatic curry broth is an exception. Because Northern Thailand is such a popular tourist destination, this Northern Thai curry noodle soup has become popular amongst foreigners.

Some might even say if you visit the North of Thailand and didn't eat khao soi, you didn't really make it there! It's a truly unique dish, and with this recipe you can recreate the experience of Northern Thailand at home.

What is Khao Soi and Where Did it Come From?

Khao soi ข้าวซอย is a northern Thai noodle soup that uses wheat-based egg noodles and is served in a coconut milk curry broth. It's typically made with chicken or beef, and the bowl is topped with crispy deep fried noodles. Although it is sometimes called "Chiang Mai Noodles" in the West, it is not unique to, nor originated from, Chiang Mai. 

Khao means rice and soi means to julienne. It's an interesting name because there is no rice involved in the process. Some say this is because the dish used to use rice noodles made by julienning sheets of dough. Others say khao is short for khao salee which means wheat. Yet some think that the word came from a similar Burmese dish called ohn no khao swe, which I think is more likely because the two dishes are really quite similar.

The exact origin of khao soi is debated, but the prevalent theory seems to be that it came into northern Thailand via Chinese-Muslim immigrants from the Yunnan region, which is why khao soi is not usually made with pork; despite the fact that pork is the most common meat in Thailand.

The Yunnanese, or jeen haw in Thai, would've had to travel through Myanmar in order to get to Northern Thailand, so it is possible that they encountered ohn no khao swe there and brought it with them to Thailand, hence the similarity of the two dishes.

Khao soi in Thailand can vary significantly. This is because after khao soi arrived in Thailand, in whatever form that was originally, Thai people in various places started to modify the dish to suit their own palate. So when you're in Northern Thailand, don't just try one khao soi and think you've "been there done that!"

For example, in northern Thailand you can find something called "Yunnanese khao soi" that bares almost no resemblance to this recipe - the broth has no coconut milk, and the noodles are big fat rice noodles. Aside from the fact that they're both noodles in soup, and a few common ingredients...there is very little else alike. This is possibly as close to the "original" khao soi as it gets.

Noodle Soup Ingredients

• Coconut milk, read about how to choose good coconut milk here.
• Chicken drumsticks or drumettes. Drumsticks are the most common in Thailand as the bones make the broth rich and flavourful. If you're short on time, use drumettes and they will cook in half the time of drumsticks. You can substitute boneless chicken with some caveats; see more on this in the FAQ below.
• Soy sauce. It might surprise you to see soy sauce used in a Thai curry, but that's because this is a dish of Chinese Muslim origin! See more on the history of khao soi above.
• Fish sauce. Optional, I use fish sauce to do my final seasoning adjustment because I like the flavour, but you can also just use more salt or soy sauce.
• Palm sugar, finely chopped. But brown or granulated is fine also.
• Wheat-based egg noodles, also known as wonton noodles, can be bought fresh in the refrigerated section at Asian markets. Most commonly khao soi uses flat noodles, but sometimes round ones are used, so whatever you prefer is fine. Some of these noodles will be used for frying as crispy noodles on top.
• Chopped cilantro for garnish, optional (not pictured).

Condiments for Khao Soi

These four condiments are iconic, and khao soi is not complete if served without them! However, if you don't eat spicy, you can skip the fried chili flakes.

How to Make Khao Soi Step-By-Step

Here's a bird's eye view of the process. Since all the components can be made in advance, I recommend you spread the work out over two days to make it easier. See more on advance prep below. Also if this is your first time, I highly recommend watching the video tutorial to ensure success.

For khao soi curry paste

1. Remove the seeds from the black cardamom pods and place the seeds into a medium dry skillet along with the coriander seeds. Toast over medium high heat, moving them constantly, until the coriander seeds darken slightly. Set aside.
2. In the same skillet over high heat, place the ginger and turmeric slices down and let them sear until they're slightly charred. Then flip and char the other side and remove from the pan.
3. In the same skillet, add the shallots and let them char; stirring them around to char them more evenly. Remove from the pan.
4. Cut the chilies into chunks and pour out most of the seeds.

5. In a coffee/spice grinder, grind the chilies, black cardamom and coriander seeds into a powder, remove and set aside.
6. In a heavy-duty mortar and pestle, pound the ginger and turmeric into a fine paste. (*You can also double the recipe to get more volume and use an immersion blender, as shown in my red curry paste recipe.)
7. Add the shallots and the coarse salt and pound; and once it starts to get wet and slippery, add some of the ground spices to help absorb moisture and add friction.
8. Pound into a fine paste, then add any remaining dried spices and pound to mix.

For khao soi broth

9. Add ½ cup (120 ml) of the coconut milk and bring to a boil over medium heat. Add the curry paste and stir for a few minutes until the mixture is very thick and coconut oil starts to sizzle around the edges of the paste.
10. Add the remaining coconut milk and stir to dissolve the paste. Then add water, soy sauce, black soy sauce, and sugar.
11. Add the chicken drumsticks and bring to a simmer. Simmer gently for 40 minutes or until the drumsticks are fork tender. (Now's a good time to prep condiments and fry the noodles.)
12. Taste and adjust seasoning, adding more fish sauce if it needs a little more salt.

13. For crispy noodles: Cut the noodles for frying to about 4 inches, then fry them in a 350°F oil, pressing them down to keep them submerged. Once they are golden brown and the bubbling has almost completely stopped, remove from the oil and drain on a paper towel.
14. When ready to eat: Boil the noodles until they are fully cooked - timing will vary between brands and noodle sizes. Mine take 3 minutes. Drain and divide into serving bowls.
15. Place 1 or 2 drumsticks into the bowl and ladle the curry on top.
16. Serve immediately with the condiments.

For The Fried Chili Flakes (optional)

Of the 4 khao soi condiments, this is the only one that needs to be prepped beyond chopping, but it's a snap. It is also optional and only needed if you want to let your guests to make it spicier.

1. Add the chili flakes and oil to a small pot or skillet - you can make as much as you want here, it keeps indefinitely in the fridge. Then add just enough oil so that the chili flakes look like wet sand.
2. Turn the heat on medium low and keep stirring until the chilies start to darken and smell smoky. Transfer into a small bowl immediately to stop the cooking.

Advance Prep Tips

There are several components to khao soi, so unless you're doing this as a weekend project, I suggest you break the work up over a couple of days. Here are the things you can do ahead of time and how to store them.

• Make the curry paste in advance. If you do one thing in advance, this should be it. Make the curry paste, and then if you'll be cooking the curry in the next day or two, keep it refrigerated. Beyond that amount of time, you should freeze the curry paste. It can be frozen for a few months so you can make a big batch and freeze the remainder.
• Make the curry broth in advance. The broth will keep well in the fridge for up to a week. You can even freeze it in smaller portions if you want to save it for a rainy day. It will actually taste better once it's had time to sit.
• Fry the noodles in advance. The noodles can be fried and kept in an airtight container for up to a week. If you're frying them a few days ahead, fry them until all the bubbles are completely gone to make sure there is no moisture left in them. This will ensure they stay crispy for a long time.
• Prep the condiments. Getting the condiments together is the kind of fiddly thing that I hate dealing with on the day I'm busy serving guests. So I prep the condiments the day before and put them in little bowls/ramekins, put them on a plate, then wrap the whole thing and refrigerate. Then you just bring the whole plate out when ready to serve.

Frequently Asked Questions