Tom Yum Goong (ต้มยำกุ้ง)

The Soup Thailand Actually Eats

Pad thai may be the dish the world knows, but tom yum is the one on Thai dinner tables, in the ตามสั่ง rotation alongside stir-fries and curries. No one knows who invented it — the Michelin Guide notes the earliest records are of tom yum pla, the fish version, in the reign of King Rama V — and it has since branched into clear (nam sai), creamy (nam khon), dry (Jay Fai's famous version) and even fried rice.

The ancient form is clear and not sweet. Chef Ou (Sittikorn Chantop) of AKKEE — 1 Michelin star and the 2025 Michelin Young Chef Award — describes his as "ancient Thai style, not sweet, with no milk or cream of any kind." His richness comes from prawn tomalley fried with herbs, never from dairy. And every serious Thai source shares one rule: the lime goes in after the heat is off. Boiled lime turns bitter — this is the legendary fix between an average tom yum and a great one.

The Recipe (nam sai — clear, for 2–3)

The Method

1. The stock. Prawn heads and shells into the water, hard boil 15 minutes, skim the scum, strain. This is the heart — plain water gives you a plain soup. (Chef Ou simmers his a full hour with shallots, lemongrass and coriander root for depth.)
2. The aromatics. Stock back in the pot. Mature galangal, lemongrass, coriander roots, shallots — hard boil 5 minutes to pull the fragrance out.
3. Mushrooms in, 1 minute.
4. Prawns last. Only at a full rolling boil. The moment they curl and turn orange, off the heat — 70% is done, the residual heat finishes them. Overcooked prawns shrink and turn rubbery.
5. Season off the heat. Fish sauce first, then the lime. Heated lime turns bitter — this is the rule. Chef Ou squeezes it straight into the serving bowl.
6. Finish. Bruised chillies, torn makrut leaves, sawtooth coriander. Lid on, 30 seconds.
7. Taste. Sour leads, then salty, then hot. Serve immediately.

The Nam Khon Variant

The creamy version is the modern restaurant adaptation — and Thai sources can't agree on how to do it, which tells you it was never canonical:

Where Thai Sources Disagree

How Western Versions Get It Wrong

• Creamy by default. The classic is clear. Western versions made coconut-cream the baseline — it isn't, and even the creamy Thai versions usually don't use coconut milk.
• Lime cooked in the pot. The single biggest technical error: heated lime goes bitter. Squeeze it off the heat, into the bowl if you want to follow the Michelin chef.
• No prawn stock. Water plus a stock cube is a thin soup. The heads and shells are the flavour — and they're free.
• Sweetened versions. Tom yum is sour-leading. The ancient recipe takes no sugar at all.
• Overcooked rubbery prawns. Off the heat the moment they curl.
• Missing or skimped galangal. It's the signature aroma — ginger is not a substitute.
• Tomato, capsicum, "Thai soup" creations. Not this dish.

UK Ingredient Notes

• Raw shell-on prawns: supermarket fish counters. Keep the heads and shells — they're the stock.
• Galangal: fresh at Asian grocers (frozen works); makrut lime leaves: Asian grocers, freeze well.
• Straw mushrooms: Asian grocers — fresh or tinned. Bird's eye chillies: any Asian grocer.
• Sawtooth coriander (culantro) is optional; ordinary coriander leaves for garnish.
• Thai "แป้น" limes aren't sold in the UK — regular limes are fine, just squeeze them off the heat.

Sources

This recipe is translated from the following Thai-language sources. Where they disagree, we've said so.