Garlic

Garlic should be kept in a dry and cool enviroment or as time goes by it will sprout. This greenish hard centre causes indigestion and the sensation that we have been eating it all day. 

 
To avoid it (it does not reduce taste) split the clove in half lengtways and prick it out. Then chop or mince the clove as needed. Make sure you run your hands and knife under the cold tap without rubbing and the smell goes.( the smell comes from the oil so if you rub your hands you are actually massaging it in).  
In Spain we have a saying "ajo cocido, ajo perdido" meaning, garlic should always be fried, therefore it is the first ingredient when making sauces, sautees and so on. Once it is "dancing" you can add the rest of the ingrdients.