And drinking onion juice. People laugh, but a 300% increase in rats should be enough of a reason for futher inquiry. https://www.ergo-log.com/onionjuice.html

and also "the only human study that directly link between onion and testosterone reveal a positive effect of onion extracts on testosterone" https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6406961/#!po=9....