Cook · Fish

Masor Tenga

মাছৰ টেঙা

The sour fish curry that closes an Assamese meal — clean, light and completely unforgiving of a heavy hand.

Chef Name·24 August 2026·5 min read

A pale golden Assamese sour fish curry with a red chilli, in a steel bowl.
01

The story

Tenga is the last thing served at an Assamese lunch, and for most of my childhood I thought that made it the least important — a rinse, a full stop, the thing you had after the food. It took a professional kitchen to teach me that the dish placed at the end of a meal is usually the one doing the hardest work.

A tenga has nowhere to hide. There is no browning, no masala paste, almost no fat once the fish is fried. The broth is nearly transparent. Every decision — how long the fish sat in salt, when the sour went in, whether you let it boil — is visible in the bowl. I have cooked it perhaps two hundred times and I still get it wrong when I am not paying attention.

This is the version I cook now: tomato and ou tenga together, because one gives body and the other gives the particular resinous sourness that tomato cannot.

02

About the dish

Origin
A daily dish across the Brahmaputra valley rather than a festive one — the kind of cooking that exists because a river runs through the state and freshwater fish is ordinary rather than special.
Region
Assam, and by extension much of the Brahmaputra floodplain.
Cultural significance
Assamese meals are ordered by taste, not by course. Khar — alkaline — opens the meal; tenga — sour — closes it. The two sit at opposite ends of the same plate deliberately, and eating them in the wrong order feels wrong to anyone raised on it.
Flavour profile
Sour, saline, faintly bitter from the fenugreek, and clean. There is no chilli heat to speak of and no ground spice at all beyond turmeric.
03

Ingredients

The fish

  • 600 g rohu or any firm freshwater fish cut into 2 cm steaks, on the bone
  • 1 tsp turmeric
  • 1 tsp salt
  • 4 tbsp mustard oil for frying

The broth

  • ½ tsp fenugreek seeds (methi) the only tempering — do not substitute
  • 2 ripe tomatoes roughly chopped
  • 80 g ou tenga (elephant apple) fresh, sliced — or 2 dried pieces, soaked
  • 2–3 green chillies slit, not chopped
  • ½ tsp turmeric
  • 750 ml water
  • to taste salt

To finish

  • a handful coriander leaves torn, off the heat
  • 1 tsp raw mustard oil optional, but this is how it is done at home

Substitutions & notes

  • No ou tenga: use an extra tomato plus a squeeze of Assam lemon at the very end. You lose the resinous note but keep the balance.
  • Dried thekera (Garcinia) works in place of ou tenga and gives a rounder, less sharp sourness — use two petals.
  • Sea fish is a poor swap. The dish is built for the sweetness of freshwater fish; anything oily will fight the broth.
04

Method

  1. Step 01

    Prepare

    1. Rub the fish steaks with the turmeric and salt and leave them for 15 minutes. This is not seasoning — it firms the surface so the pieces survive the pan.
    2. If you are using dried ou tenga, cover it with warm water now and leave it to soften.
  2. Step 02

    Fry the fish

    1. Heat the mustard oil until it just begins to smoke, then take it off the heat for thirty seconds. Raw mustard oil is aggressive; this drives off the harshness.
    2. Fry the fish in a single layer, two minutes a side, until the surface is set and pale gold. It does not need to cook through — it will finish in the broth.
    3. Lift the fish out and set it aside. Keep the oil.
  3. Step 03

    Build the flavours

    1. Into the same oil, add the fenugreek seeds. Give them about ten seconds — until they darken by one shade and smell nutty. A second too long and the whole pot turns bitter; this is the single most common failure in the dish.
    2. Add the tomatoes, green chillies and turmeric with a pinch of salt. Cook until the tomatoes collapse completely, four to five minutes.
    3. Add the ou tenga and press it lightly against the side of the pan.
  4. Step 04

    Simmer

    1. Pour in the water and bring it to a gentle simmer. Season, and let it run for eight minutes so the sourness distributes — the broth should taste sharp on its own.
    2. Slide the fish back in. From here it is five minutes at the barest tremble. Do not boil it and do not stir it; move the pan, not the fish.
  5. Step 05

    Finish

    1. Take the pan off the heat. Tear in the coriander and, if you like, trickle in the raw mustard oil.
    2. Rest it for five minutes before serving. The broth clarifies slightly and the sourness settles.
    3. Serve last, with plain rice.
05

Palateful notes

What I learned

  • The fenugreek is the whole tempering and it is measured in seconds, not minutes. Pull the pan the moment it smells like toasted nuts.
  • Sourness should be built in the broth before the fish returns. Adding acid at the end tastes bolted on, because it is.
  • A tenga is supposed to be thin. If it coats the spoon, there is too much tomato in it.

Common mistakes

  • Boiling the fish. The pieces break up and cloud the broth, and the clarity is half the dish.
  • Burnt fenugreek. There is no rescue; start the tempering again.
  • Chilli powder. It has no place here and turns a clean broth muddy.

Variations

  • Kosu thuri (colocasia stem) instead of tomato gives a more traditional, more austere version.
  • Fried potato added with the broth turns it into a fuller one-pot meal — common in home kitchens, frowned on by purists.

What I would change next time

I want to try holding back half the ou tenga and adding it in the final two minutes, to see whether the sourness reads in two layers rather than one. The risk is that it never integrates and just tastes raw.

  • Assamese
  • Sour
  • Fish
  • Everyday
  • Mustard oil
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