Pla Pae Sa (ปลาแป๊ะซะ)

One Name, Three Sauces

Kapook's editors unpack the name: แป๊ะ (pae) means white, or plain, and ซะ (sa) means boiling something in plain water or stock and ladling the liquid over it — a Teochew kitchen technique, not a dish. The plate that kept the name is the old Chinese one: a whole snakehead steamed and laid on cabbage, drowned in a light, sour-sweet broth of pickled plum, pickled garlic and ginger, eaten with a fermented soybean dip on the side.

Then the name ran loose. The version that dominates Thai restaurant menus today is a whole fish deep-fried until the skin crackles, then drowned in a pot of แกงส้ม sour curry — the version Kapook itself describes as the recipe being adapted to Thai tastes. And in Isaan, แป๊ะซะ means something else again: the sauce. Garlic, fresh chilli and coriander root, pounded in a mortar with roasted peanuts — sharp, salty, faintly sweet — served beside a fried or grilled fish. Same words, three dishes, and every one of them worth eating.

The recipe below is the Isaan way — the deep-fried fish with the pounded sauce — with the other two families written out in full, because the Thai sources do not agree, and neither should a page that pretends they do.

The Recipe (Isaan home version — sauce from Pantip, fish-frying from Aroifin and Wongnai)

The Pantip thread that this sauce comes from gives no quantities — its cooks season by taste, which is how the sauce behaves. The Chinese pot (Kapook): a 700–800 g snakehead steamed 8–10 minutes, laid on cabbage, drowned in a litre of stock boiled with 3–4 pickled plums and 3 tablespoons of their brine, 3 heads of pickled garlic with 1–2 tablespoons of its juice, shredded ginger, a tablespoon of ground white pepper, light soy and a little rock sugar — celery, spring onion and sliced chillies scattered on top. The sour-curry pot (Aroifin): a fried whole fish in a hot pot with 150 g of แกงส้ม paste — Aroifin boils a second, smaller fish and pounds its flesh into the paste — seasoned with 2 tbsp palm sugar, 1 tbsp white sugar, 6 tbsp fish sauce, ½ tsp salt and 12 tbsp tamarind water, over blanched white cabbage, yardlong beans and lotus stems.

The Method

1. Clean the fish. Scrape the scales, gut it, then rub the skin with coarse salt and a little tapioca starch until the slime lifts, and rinse. Aroifin uses this salt-and-starch scrub specifically to kill the fishy smell — Kapook offers the same trick with salt and tamarind water.
2. Score it. Cut deep diagonal slashes down to the bone on both sides. The slashes let the heat in, so a thick fish cooks through while the outside crisps.
3. Fry it. Oil hot and deep enough to cover the fish. Lower it in and leave it alone — Aroifin times 8–10 minutes a side and warns against moving the fish early, or the skin won't fluff. Turn once, fry the second side, lift out and drain.
4. Pound the aromatics. Fresh chillies, garlic and coriander roots into the mortar first — pound them fine. This is the base of the sauce and it cannot be done in a blender the same way; the pounding draws the oils out of the roots.
5. Pound the peanuts. Roasted peanuts go in next, pounded until broken but still nubbly. The Pantip cooks are specific: rough, never a paste — the nubs are the texture of the sauce.
6. Season and thin. Sweet chilli sauce, fish sauce, lime juice — then taste. The thread's rule: the chilli sauce is already sweet, so sugar only if you must, and cooled boiled water if the sauce is too thick. One of the thread's cooks adds MSG; the rest leave it out.
7. Serve. The hot fish on a platter, the sauce in a bowl beside it, rice and raw vegetables to go with. Spoon the sauce over the flesh or dip as you eat — Wongnai's cook eats his version with rice or as drinking food, and the Isaan sauce works the same way.

Where Thai Sources Disagree

How Western Versions Get It Wrong

• Treating it as one fixed dish. There is no single "pae sa sauce" that covers all three families. A jar of sweet chilli sauce over steamed fish is nobody's version of this dish — the Chinese pot is pickled plum and garlic, the restaurant pot is sour curry, the Isaan pot is a mortar sauce.
• Skipping the mortar. The Isaan sauce is pounded — chillies, garlic and coriander root first, then roasted peanuts until nubbly. Blending everything smooth, or opening a bottle of sweet chilli sauce and calling it done, produces something sweet and flat with none of the texture.
• Filleting the fish. Every Thai source serves the fish whole — head, bones, skin and all. The whole fish holds its shape through the fry, and the skin is the point. A fillet "pae sa" is a different, lesser dish.
• Moving the fish in the pan. Aroifin's rule is 8–10 minutes untouched, one turn. Fidgeting with the fish tears the skin, and the crisp, fluffy outside never happens.
• Over-salting the broth early. Kapook warns that the pickled plums give up salt as the soup sits and cools — season lightly, and let people correct at the table. A western habit of seasoning hard at the stove makes the Chinese version inedible by the end of the meal.
• Over-sweetening. The Isaan sauce takes its sweetness from the sweet chilli sauce; the thread's cooks add sugar only as a last resort. A western "balanced" version with extra sugar reads like bottled dip.

UK Ingredient Notes

• Snakehead (ปลาช่อน) isn't sold here, and the Thai sources themselves swap freely — Cookpad uses tilapia. A whole sea bass, sea bream or tilapia at 700–800 g works; Asian grocers often sell tilapia live.
• Coriander roots (รากผักชี): buy coriander with the roots still attached at Thai or Vietnamese grocers; if all you can find is trimmed, use the lowest, thickest part of the stems.
• Roasted peanuts (ถั่วลิสงคั่ว): dry-roast raw peanuts yourself in a pan — one of the Pantip cooks says shop-bought peanut brittle never smells or tastes as good.
• Sweet chilli sauce (ซอสพริก): the Thai-style bottle used for ไก่ทอด — thin and glossy — not the lumpy Western table condiment.
• For the Chinese pot: pickled plums (บ๊วยดอง) and pickled garlic (กระเทียมดอง) in jars at Thai grocers; for the sour-curry pot, ready-made แกงส้ม paste (Mae Pranom or similar).

Sources

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