Cut the string bean tips off.

Place the beans in a steamer basket and cook in a pot until tender, around 8 minutes.

Once the green beans are cooked, remove from heat and place in a serving dish.

Add the tomatoes, red onion, and crumbled feta to the green beans.

In a small bowl, mix the red wine vinegar, olive oil, and dried oregano together.

Drizzle the dressing over the salad, then add salt and pepper to taste.