1. Wash the fish pieces and let them air-dry for some time. Smear them with ½ tsp each of salt and turmeric and set aside while you prep the vegetables.
2. Cut the cauliflower in large florets; make incisions on the stalk if it is too thick to allow it to cook faster.
3. Peel and cut the potato longitudinally in 3cm thick wedges. Roughly chop the tomato
4. Slit the green chillies.
5. Heat mustard oil a kadai, and wait for it to smoke gently and change colour to a pale yellow.
6. Fry the dal’er bori (optional) for 20 seconds until it is golden-brown. Remove from the oil and set aside.
7. In the same oil, fry the marinated fish in a single layer (you may have to do this in multiple batches). Fry on medium-low heat for roughly 2–3 minutes on each side until brown and crisp. Remove from the oil and set aside.
8. Now add the cauliflower florets. Fry them on low heat until fragrant and brown. Keep the pan covered while you fry, and mid-way through the process add ¼ tsp each of salt and turmeric. Once brown, remove from the oil and set aside.
9. To make the curry, temper the same oil (you may have to top it up if the cauliflower has absorbed most of it) with bay leaf, cardamom, cinnamon and cumin seeds.
10. Add potatoes and fry them on low heat, covered, until brown (about 5 minutes).
11. Add tomato and fry another 2 minutes.
12. Make a slurry of cumin powder, turmeric, red chilli powder and salt. Add it to the pan.
13. Braise the spices on low heat, pan covered, for about 3–4 minutes. Add splashes of water whenever the pan runs dry and continue braising.
14. Add ginger paste and fry another 3–4 minutes.
15. Add the fried cauliflower and green chillies, and braise everything together until the potatoes and cauliflower florets have softened slightly.
16. Add hot water to form the curry. Once it comes to a boil, add the fried bori.
17. Giving the bori a couple of minutes of head-start, lower the fried pieces of fish.
18. Bubble until the potatoes and cauliflower have softened and the curry has thickened slightly (about 5 minutes or so).
19. Add in the sugar and sprinkle some atta (to thicken the curry).
20. Once you are happy with the consistency, finish with bengali garam masala and freshly chopped coriander leaves.