Soak black soybeans (Bhatt) overnight and pressure cook until tender.
Dry roast rice flour until it turns light golden and aromatic.
Heat mustard oil in a pan and add cumin seeds and a pinch of asafoetida.
Add ginger-garlic paste and sauté briefly, then mix in turmeric, coriander powder, and red chili powder.
Stir in the roasted rice flour and gradually add water, whisking to form a smooth gravy.
Add the cooked black soybeans and simmer for 15–20 minutes until the curry thickens.
Garnish with fresh coriander leaves and serve hot with steamed rice or mandua roti.