Kassod tree leaves and a leafy Thai curry with grilled fish (gaeng khiilek)

IMG_5037I am back after a nearly four month hiatus. Although I didn’t report on them as they were happening, over these past several months I was fortunate enough to have many incredible food experiences in Mongolia, China, Thailand, and Indonesia–experiences that I will reflect upon as I post going forward this fall.

Most recently I was in Thailand for a week. Food was of course, wonderful. Of particular note and following a trend of my own recent food interests, I appreciated the incredible diversity of vegetal leaves, sprigs, vines, and pods in local cuisines of North and Northeastern Thailand. I tend to be drawn to dishes that include a lot of greens, and in Thailand this idea goes way beyond “salad”. Today, back in Philadelphia, I am cooking to recreate one such food memory of a leafy curry—a curry that is simply named after the savory leaves of the kassod tree (Senna Siamea-see here for an image search of what these trees and flowers look like). In Thai, the name is khiilek ขี้เหล็ก.

IMG_5047English names for this tree vary: kassod, cassod, [Siamese] cassia. To keep things simple, I will refer to them by the Thai name, khiilek (pronounced “keelek”). The leaves and flowers of this tree taste a bit like cardamom, but the leaves should not be eaten raw due to a toxin that can damage the liver. If you have fresh leaves/flowers available, they should be boiled and squeezed of water 2 or 3 times before using in final cooking preparations.

Because of its toxicity in its raw state, as a cooking ingredient khiilek is generally used in soups throughout Thailand and Myanmar. In Thailand, the dish gaeng khiilek แกงขี้เหล็ก, or “khiilek soup” can be found in most any rice and soup stand or market. There are regional variations, however, with what goes into this “soup”. You can get a sense of regional diversity by seeing an image search for khiilek soup. You may notice that the soup seems to come in different colors: dark brown, green, and a pale orange. This difference is primarily whether the soup base is a coconut curry (popular in Southern, Central, North-central Thailand), or as an herbal soup, as it is in Northeastern Thailand.

Today I am trying the coconut curry version.


“Pickled Cassia Leaves”. I wouldn’t have used the word “pickled” but rather “canned”. It is nice to see new imports from Thailand with nicer labeling, however.

I found the leaves in jarred form at a Cambodian market in North Philadelphia, Seng Hong market. As usual, I checked the name in Thai to be sure I was buying the thing I thought it was. If you cannot do this, ask the shopkeeper (smaller shops in North and South Philly are best for this). This can be found in the jarred/canned Southeast Asian section of the market. At the large markets on Washington Ave, the jars don’t have Thai writing, but are labeled as “Cassia”.

Today’s effort was kind of experimental, based heavily on research of Thai language blog posts and videos. The curry paste that is generally used for khiilek coconut curry is basically the same as red curry paste (namprik gaengdaeng น้ำพริกแกงแดง), with the addition of rhizome (grachai กระชาย) and tumeric. I followed the advice of Pim and her great blog, “Pim’s family kitchen” ครัวบ้านพิม to use ready-made red curry paste instead of doing that from scratch. Other examples online puree the leaves to produce an effect that is a thick soup. Some may find this a more attractive option, and a good example can be found in a Thai FoodTravelTV video here.

The results were tasty, and I was surprised with the flavor (especially as I was using canned leaves). Below is my first attempt.

Kassod leaf curry with grilled fish – gaeng khiilek plaa yang – แกงขี้เหล็กปลาย่าง

Below are images with captions of other the key ingredients besides khiilek leaves. Approximate amounts: 1 16 oz jar of khiilek leaves, Japanese mackerel, 1/2 lb of pork ribs, 1-2 Tblsp rhizome, 1-2 Tblsp palm sugar, 2 cups coconut milk or cream, water if too thick, fish sauce to taste.

  • Grill fish. I used a charcoal grill with hardwood charcoal. My fish was a Japanese mackerel (cleaned) that was seasoned with a little salt. Grill until golden and crispy on all sides. After it is cool, hand shred the fish meat and remove bones if they will be a nuisance. Parboil pork ribs (optional, and probably less important as this is an opaque curry anyway).
  • Drain and soak khiilek leaves in lots of water. Drain and squeeze dry.
  • Chop rhizome and mash in mortar and pestle. Fry the red curry paste and rhizome in a little oil. Add in the shredded grilled fish and pork ribs.
  • Add in khiilek leaves, and add sugar and more coconut milk/cream or water to cover. Bring to boil.
  • Taste for final seasoning and add palm sugar and/or fish sauce to balance flavors.

Next time I make this, I will experiment with colors and perhaps puree about half of the leaves.

About David Dettmann

Food obsessed and frequently nostalgic.
This entry was posted in - Featured Food Discoveries, - Recipes, Thai/Lao food and tagged , , , , , , , , , . Bookmark the permalink.

1 Response to Kassod tree leaves and a leafy Thai curry with grilled fish (gaeng khiilek)

  1. La says:

    Yeah, if I remember correctly, in Thailand the leaves are pureed.

    Liked by 1 person

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