This recipe is from "Martha Stewart's Hors d'Oeuvres Handbook."

2 cups Picholine olives (8 to 10 ounces)

1/2 cup plus 1 tablespoon extra-virgin olive oil

4 cloves garlic, thinly sliced lengthwise

1/4 cup plus 2 tablespoons champagne vinegar

1/2 small red onion, thinly sliced

2 dried bay leaves

1 tablespoon mixed (red, white, green) peppercorns, slightly crushed

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.