Hero ingredient - guanciale (face bacon)
A delicacy traditionally from Umbria. As with any true delicacy, it tastes better than the sum of its parts. Some purists say that a true carbonara has to have lardons made from guanciale.
WHAT IS IT? Cured pig jowls and cheeks that have been preserved with salt, spices and wine. The fat is the best bit here and has real melt in the mouth qualities.
WHAT DO I DO WITH IT? A carbonara obviously. Beyond that, I have been known to have it as a replacement for bacon in pretty much every situation, including a bacon sandwich.
WHERE CAN I FIND IT? Good Italian delis or online - they sell it at Vallebona (warning, this site is meat porn)