First of all we can say the answe is no onion 🙂 Think another things.
Riddle: What can burn the eyes, sting the mouth, yet be consumed?
Most people probably have experienced their eyes burning when interacting with salt. This situation is most possible to happen in a sea or an ocean. If you open your eyes while swimming and do not have any protection for your eyes, salty seawater burns your eyes.
Moreover, all people use salt in their foods in a certain amount. Even though one’s slat tolerance is very personal if you use too much salt in your dish, the salt will sting your mouth. Yet, these facts are not stopping people from consuming salt, for it is one of the main ingredients of different cuisines. The answer of this riddle is salt.
Answer is : Salt.