Combine the olives, feta, olive oil, lemon zest, lemon juice, garlic, oregano, and red pepper flakes in a bowl and stir gently so the feta cubes stay whole.

Cover and marinate in the refrigerator for at least 2 hours, or up to 2 days, stirring once halfway through.

Bring the mixture to room temperature for about 20 minutes before serving, which wakes the olive oil back up.

Spoon the olives and feta evenly into 10 small cups or jars, dividing the oil at the bottom among them too.

Tuck a small thyme sprig into each cup for garnish.

Set the cups on a tray with small forks or cocktail picks alongside, since the feta is easiest to eat speared rather than with fingers.