Place potatoes in a medium saucepan.

Cover with water.

Bring to a boil.

Reduce heat and simmer for 20 minutes.

Add green beans and cook for 1 1/2 minutes.

Drain and rinse with cold water until cool.

Cut potatoes into quarters.

Place potatoes and beans in a large bowl.

Add halved cherry tomatoes and finely chopped red onion.

Toss gently to combine.

In a small bowl, combine extra-virgin olive oil, white wine vinegar, whole-grain Dijon mustard, fresh thyme leaves, salt, and freshly ground black pepper.

Stir with a whisk.

Pour the dressing over the potato mixture.

Toss gently to coat.

Stir in chopped fresh parsley and pitted, quartered Kalamata olives just before serving.