Potato cooked in a thick, sharp paste of mustard seeds and white poppy seeds — the combination of two of Bengal's most characteristic spice pastes applied to the most common vegetable. The mustard-poppy combination creates a flavour profile found nowhere outside Bengal.
Ingredients
4 medium potato — peeled and cut into medium cubes
For the paste:
2 tbsp yellow mustard seeds — soaked 20 minutes
2 tbsp white poppy seeds (posto) — soaked 20 minutes
Make the mustard-poppy paste: Drain soaked mustard and poppy seeds. Grind together with green chilli, turmeric and salt. Add 3 tbsp water. Grind 4 minutes to a very smooth paste. Mix in 2 tbsp raw mustard oil.
Coat the potato: Toss the potato cubes with the ground mustard-poppy paste. Let them sit coated for 10 minutes.
Heat mustard oil: Heat 3 tbsp mustard oil until smoking. Reduce to medium.
Add kalonji: Add nigella seeds — they crackle in the hot oil.
Add the coated potato: Add the potato cubes with all the paste. Stir to combine with the hot kalonji-infused oil.
Cook on medium heat: Cook stirring every 2 minutes for 5 minutes as the paste cooks and dries slightly around the potato.
Add a little water: Add 1/4 cup water. Stir. Cover and cook on medium-low heat for 10 minutes until the potato is fully tender.
Uncover and dry: Remove the lid. Cook 3 more minutes to reduce any excess liquid. The paste should coat each potato cube in a thick, dark-yellow layer.
Taste: The shorshe posto aloo should be sharp from the mustard, subtly creamy from the poppy seeds and pungent from the raw mustard oil.
Serve: Serve with steamed rice and dal.
Note: Shorshe Posto Aloo combines the two most distinctly Bengali spice pastes — shorshe (mustard) and posto (white poppy seed) — in a single preparation. In Bengal, posto (poppy seed) is used as a culinary spice in quantities and applications found nowhere else in India — it is used to thicken, to add creaminess and as a flavour element. The combination of mustard and poppy together is a specifically Bengali flavour signature. The dish requires no elaborate technique but is deeply flavoured from the high-quality mustard oil and the combined paste.