This recipe, from "Martha Stewart's Hors d'Oeuvres Handbook," is an easy make-ahead dish that goes over well at parties
Place olives in a medium bowl; set aside. Heat 1 tablespoon olive oil in a small skillet over medium-low heat. Add garlic; cook just until golden, about 2 minutes. Transfer garlic to a paper towel to drain, and let cool; set aside.
Bring 2 tablespoons vinegar and red onion to a simmer in a small saucepan over medium heat; reduce by half to 1 tablespoon. Add remaining 1/2 cup olive oil, 1/4 cup vinegar, bay leaves, and peppercorns; bring to a simmer. Stir in garlic. Pour warm mixture over olives, and marinate at room temperature for at least 2 hours. Olives may be made 1 week ahead, and refrigerated in an airtight container. Return to room temperature before serving.