Place beans in boiling water seasoned with 1 teaspoon salt; cook 6 to 8 minutes or until crisp-tender. Drain. Plunge beans into ice water to stop the cooking process. Place in a shallow serving dish.
Cook garlic in hot oil in a skillet over medium heat 30 seconds or just until fragrant; remove from heat. Stir in olives, next 4 ingredients, and remaining 1/2 teaspoon salt. Pour mixture over beans, tossing to coat. Chill at least 3 hours or overnight. Sprinkle with feta cheese. Garnish, if desired.