Virtually every train station vendor keeps at their stall a tin of panch phoron, a whole-spice blend that perfumes the air with earthy cumin and lively fennel seed as they liberally sprinkle it on savory dishes like mutton curry and spicy prawn curry. Known as “Indian 5-spice,” it’s a traditional flavoring in Bengali cooking. Unlike many other Indian spice blends where the spices are blended into a powder, the five spices in panch phoron are left whole. If you have trouble sourcing nigella seeds, which can be found at Indian markets, substitute black sesame seeds. Store this in a covered container in a dark place for up to 6 months.
Heat a dry pan over medium heat until a mustard seed pops a few seconds after it hits the surface of the pan, 3 to 4 minutes. Add the cumin and toast until aromatic, swirling the pan as it toasts, about 1 minute. Transfer to a plate and repeat with the remaining spices, toasting each one separately. Cool the spices to room temperature and then transfer them to an airtight covered container and shake to combine. Store up to 6 months in a cool, dry, dark place.