A common one is cilantro, these people have a variation in a group of olfactory-receptor genes that allows them to strongly perceive the soapy-flavored aldehydes in cilantro leaves. This genetic quirk is usually only found in a small percent of the population, though it varies geographically. Interestingly, places where cilantro is especially popular, such as Central America and India, have fewer people with these genes, which might explain how the herb was able to become such a mainstay in those regions. East Asians have the highest incidence of this variation, with some studies showing that nearly 20% of the population experiences soapy-tasting cilantro. https://www.britannica.com/story/why-does-cilantro-taste-like-soap-to-some-people