If olives are in brine, drain and discard liquid. Toss all the olives together in a bowl. Toss with a generous amount of olive oil, lemon zest, red pepper flakes, rosemary sprigs, salt, and slivers of fresh garlic. Let marinate at least overnight and up to a couple weeks in the refrigerator - they'll only get more flavorful.
Recipe courtesy of Dave Lieberman