Gather the seeds and rinse them thoroughly. If you do this in a metal sieve it kind of rubs off the scales as they swirl around in the water, failing that just squish them around in a mug with a fork. Drain off and then bash them with something; mortar and pestle at home, a stick in your mug when out. Pour over hot water and bring slowly to a simmer. Turn off heat and allow to sit....it's a bit like couscous to make.
The reason for bashing the seeds is to allow them to soften in the water water more easily, it's not necessary if you have time and equipment to let them simmer for while. The seeds swell up with a clear gelatinous coating like quinoa but greeny brown and not so tidy looking.
Seeds like plantain and docken are usually parched before use, that is scorched or tossed above flames, to burn off the husky bits. This is fine if you know what you're doing, if you get it wrong dinner is ash though
Personally, parched and bashed seeds are added to stew to thicken and enrich it.
cheers,
Toddy