Marinated Green Beans with Tomatoes, Olives, and Feta

This marinated green bean salad is a wonderful spring side dish. The Kalamata olives, tomatoes and feta give it a Greek twist and an incredible blend of flavors. Allow the flavors to marinate together overnight for even better results.
Ingredients
2 pounds fresh green beans, trimmed
¼ cup olive oil
2 cloves garlic, minced
1 cup kalamata olives, pitted and sliced
2 tomatoes, seeded and chopped
2 tablespoons red wine vinegar
1 tablespoon chopped fresh oregano
½ teaspoon salt
¼ teaspoon ground black pepper
1 (8 ounces) package of crumbled feta
1 bunch of fresh oregano sprigs