Combine the ginger & garlic paste, coriander powder, cumin powder, hing, turmeric, and Kashmiri chilli powder in a bowl.
Add 2 tbsp water gradually while whisking to create a smooth, lump-free paste.
Set aside for later use.
Marinate the Fish
Place fish pieces in a bowl and sprinkle with salt and turmeric powder.
Gently rub the marinade into each piece, ensuring even coating.
Let marinate for 15-20 minutes while preparing other ingredients.
Fry the Components
Heat mustard oil in a cast iron pan over medium-high heat until it begins to smoke slightly.
Carefully add marinated fish pieces and shallow fry for 2 minutes on each side until golden brown.
Remove fried fish and place on a plate lined with paper towels.
Add potato wedges to the same oil and fry until they're golden and tender, about 4-5 minutes.
Remove potatoes and set aside with the fish.
Build the Curry Base
Add panch phoran to the remaining oil and let the seeds crackle and release their aroma, about 30 seconds.
Add sliced onions and sauté until golden brown and fragrant, about 5-6 minutes.
Add diced tomatoes and cook until they become soft and pulpy, and oil begins to separate, about 5-7 minutes.
Season with salt and Kashmiri red chilli powder, mixing well.
Stir in the masala paste and cook for 5 minutes until the raw smell disappears. stirring frequently to prevent sticking.
Pour in water and bring the mixture to a rolling boil.
Gently add fried fish
fried potatoes to the pan.
Reduce heat to low and simmer for 15 minutes until potatoes are fully cooked and flavors have melded.
Garnish with fresh coriander leaves and remove from heat.
Notes
Serving & Storage NotesServe immediately with steamed basmati rice or plain white rice for an authentic Assamese meal. The curry tastes even better the next day as the flavors develop further.Storage: Refrigerate for up to 3 days. Reheat gently on low heat, adding a splash of water if needed.Substitutions: If rohu is unavailable, use any firm white fish like catla, pomfret, or even salmon. Wild celery seeds (radhuni) can replace cumin seeds in the panch phoran for a more authentic Bengali flavor.The beauty of this dish lies in its simplicity and the aromatic panch phoran that infuses every bite with the essence of Eastern Indian cuisine.