Bring a pot of salted water to a boil. Add the green beans and cook for 3-5 minutes until bright green and tender-crisp.

Drain the green beans in a colander and immediately transfer to a bowl of ice water to stop the cooking process.

In a small bowl, whisk together olive oil, red wine vinegar, Dijon mustard, minced garlic, salt, and pepper until well combined.

In a large bowl, combine the cooled green beans, cherry tomatoes, red onion, and feta cheese.

Drizzle the vinaigrette over the salad and toss gently to combine.

Serve immediately or refrigerate for 30 minutes to allow flavors to meld.