It is a mild tasting mix of whole seeds (not ground) that is definitely not spicy; the predominant taste is anise / liquorice.
It is made from five different seeds: cumin, fennel seed, fenugreek seed, nigella and radhuni (wild celery seed) in equal parts. You can buy the seeds already mixed as “Panch Phoron”, or mix up your own “Panch Phoron” at home from the various five seeds, using equal parts of each.
Outside West Bengal, the radhuni seed is hard to obtain, so people swap it for black mustard seed. Some people use celery seed as the substitute for radhuni itself, saying it gives a more accurate Bengali taste.
In this mix, the sweet taste of the fennel compliments the bitterness of the fenugreek.
Panch Phoron is toasted before use. Some recommend to do this by toasting it in a dry frying pan for 1 minute. In Bengal, this is done in hot mustard oil instead. In this way, the flavour passes into the oil, which then passes into the other foods that are added to the pan.
When the seeds pop, you are ready to proceed with your recipe.
Occasionally, the seeds might be toasted dry, and ground to a powder for use as a sprinkling garnish on dishes such as sukto and raw chutneys.
Aka “Panch Puran.”