Water Lily Stem Curry (Kaeng Bua / แกงบัว)

Ingredients

Equipment Needed

• •Heavy granite mortar and pestle (krok hin) for pounding the kreung tam
• •Medium stockpot or deep saucepan
• •Small dry pan for roasting tua nao

Instructions

1. 1

   Prepare the water lily stems

   Take each water lily stem and peel away the thin, fibrous outer skin. Run your thumbnail along the length and strip it off. Inside is the pale, slightly translucent flesh. Cut the peeled stems into 3-inch lengths. When you slice them, you'll notice they're hollow and release a slightly slimy liquid. That's normal. It's similar to okra, and it actually helps give the broth a subtle body. Soak the cut stems in a bowl of cold water while you prepare the paste. This keeps them crisp and rinses off excess slime.

   If your stems are very young and tender, the outer skin peels easily. If they resist, use a small knife. Don't skip the peeling. The outer layer is fibrous and stringy, and no amount of cooking will fix that.
2. 2

   Dry-roast the tua nao

   Place the tua nao disc (or a piece of it) in a dry pan or directly over a low flame. Roast it until it darkens slightly and the smell changes from raw and funky to toasty and almost nutty. This takes about 2 minutes. Watch it. Tua nao burns fast once it commits. When it's fragrant, crumble it between your fingers or break it with the back of a spoon. It should be dry and crumbly, not sticky.

   Tua nao replaces shrimp paste in many Lanna pastes. It gives you fermented umami, but the flavor is drier, nuttier, closer to a rough miso than to the ocean funk of kapi. If you can't find tua nao, use 1 teaspoon of red miso as a last resort, but know you're substituting outside the system.
3. 3

   Pound the Lanna kreung tam

   Start with the salt and soaked chilies in the granite mortar. Pound to a rough paste. Add the garlic and shallots, pound again until broken down but not perfectly smooth. Lanna pastes keep some texture. Now the ginger, in it goes. Pound it into the mixture. You'll notice the paste smells sharper and more peppery than a Central Thai paste. That's the ginger talking. No galangal in this one. Add the lemongrass, pound until fibrous bits are integrated. Then the turmeric, which stains everything golden. Finally, the crumbled tua nao. Pound until everything is a rough, fragrant paste. It should smell earthy, gingery, slightly fermented, with a low hum of chili heat. Not aggressive. Warm.

   Ajarn always said: the kreung tam tells you the region before the dish does. Smell this paste. No galangal, no kaffir lime, no shrimp paste. This is Lanna in a mortar.
4. 4

   Build the pork broth

   Bring 4 cups of water to a boil in a stockpot. Add the pork rib pieces. Let the water return to a boil and skim off any scum that floats to the top. Reduce to a gentle simmer and let the ribs cook for 10 minutes. The water should turn from clear to faintly cloudy with a thin layer of pork fat on the surface. That fat is flavor. Leave it. You're building a light stock here, not a consommé.

5. 5

   Add the paste to the broth

   Spoon the pounded kreung tam into the simmering pork broth. Stir it in with a ladle until it dissolves into the liquid. The broth will turn golden from the turmeric and slightly opaque from the paste. Let it simmer for another 5 minutes so the aromatics infuse fully. The kitchen should smell like ginger and lemongrass, with that background note of fermented soybean. That's how you know the paste is working.

6. 6

   Cook the water lily stems

   Drain the soaking water lily stems and add them to the broth. Stir gently. Simmer for 5 to 7 minutes. The stems should be tender but still have a slight bite, not mushy. They'll turn slightly translucent as they cook, and the broth will pick up a faint silkiness from their natural mucilage. That subtle thickening is part of the dish. Don't fight it.

7. 7

   Season and finish

   Add the fish sauce and palm sugar. Stir once. Taste. The broth should be savory first, with ginger warmth and a gentle chili heat that builds slowly. The palm sugar isn't there to make it sweet. It's there to round the edges of the fish sauce. If the broth tastes flat, add another splash of nam pla. If it tastes sharp, a tiny pinch more sugar. Toss in the green onion pieces. Stir once more. Kill the heat. Scatter the torn cilantro over the top. Ladle into bowls. Serve with sticky rice and pickled garlic on the side. That's it. The dish is done. Don't add anything else.

Chef Tips

• •Water lily stems (sai bua) are seasonal. In Chiang Mai, you'll find them bundled at Warorot Market and Muang Mai Market during the cool season, roughly November through February. Outside Thailand, look for them at well-stocked Southeast Asian markets, sometimes labeled as lotus stems. If you truly cannot source them, young lotus root sliced thin offers a distant approximation, but the texture is completely different. This is a dish worth waiting for the right season.
• •The Lanna kreung tam in this dish has no galangal, no kaffir lime, and no shrimp paste. That's not an omission. It's a regional identity. Northern Thai pastes lean on ginger for heat and sharpness, turmeric for earth and color, and tua nao for fermented depth. If you add galangal or kapi, you've left Lanna and wandered back to Bangkok. Regional differences are the system at work, not exceptions to it.
• •This is not a rich curry. It's a clear, herb-forward broth with one star ingredient. Don't try to make it more complex. The restraint is the point. Ajarn always said some dishes teach you when to add, and some teach you when to stop. Kaeng bua teaches you when to stop.
• •Sticky rice (khao niew) is the only correct accompaniment. Not jasmine rice. In Lanna, every meal is built around sticky rice. You tear off a piece, press it between your fingers, and use it to scoop the curry. The sticky rice absorbs the broth. That's the design. Jasmine rice just sits there.

Advance Preparation

• •The Lanna kreung tam can be pounded a day ahead and stored in a sealed container in the refrigerator. The flavors actually deepen overnight as the ginger and tua nao continue to meld.
• •Pork ribs can be blanched and skimmed a few hours ahead. Keep refrigerated in the blanching liquid.
• •Water lily stems should be peeled and cut the day you cook. They oxidize and lose their crispness quickly. Soak in cold water until ready to use, but no longer than a couple of hours.

Frequently Asked Questions

Nutrition Information

1 serving (about 380g)