The olive is the small, oil-rich fruit of the olive tree, picked unripe and green or tree-ripened to purple-black, and almost always cured before it is eaten because the raw fruit is mouth-puckeringly bitter. Brined, water-cured, dry-salted or lye-treated, the table olive becomes salty, savoury and fruity with a faint bracing bitterness, its dense fatty flesh wrapped around a hard woody pit — the cornerstone of the Mediterranean pantry, from Greek Kalamata to buttery Sicilian Castelvetrano.