I am not to sure I should post this, as it does indirectly encourage further seed purchase ....
..... do not throw away seeds of anything remotely brassica like, or root crops, celery, celeriac, or herbs as you can sow these very thickly in shallow trays and use the small plants at the first proper leaf stage as microgreens.
Peas and beans can be used as shoots too, only not so 'micro'
Less waste than throwing them out, and even those out of date may well have sufficient germination to succeed like this