Roasted Potao Salad with Olives

This is a recipe that I got from a friend, unfortunatly, I don't know which cookbook it came from.

Ingredients:
2 Lbs. New Potatoes, rinsed, dried, and halved
2 Tablespoons Olive Oil
1 1/4 teaspoons Herbs de Provence (mixed dried French herbs) or dried Thyme leaves
Salt and freshly ground Black Pepper
1/2 Cup pitted and coarsley chopped Kalamata Olives
1/2 small Red Onion, cut into thin slivers
2 Tablespoons chopped fresh Parsley
1 1/2 Tablespoons Rice Wine Vinegar
1 Tablespoon Mayonnaise
1 small Garlic Clove, crushed
3 Tablespoons Olive Oil

Directions: Toss the Potatoes with 2 Tablespoons of Olive Oil and Herbs, a generous sprinkling of Salt, and a few grinds of Pepper. Place the Potatoes, cut side down, in a single layer on a lipped cookie sheet. Set the pan on the lowest rack of the cold oven; heat the oven to 450°F. Roast until the cut side is golden brown and Potatoes are tender, 20 to 25 minutes. Transfer Potatoes to a large bowl; add Olives, Onion, and Parsley.

In a 2-Cup glass measuring cup, whisk together the Vinegar, Mayonnaise, Garlic, a big pinch of Salt, and a couple of grinds of Pepper. Slowly whisk in remaining Oil. Pour dressing over warm Salad; toss to coat. Serve at room temperature for best flavor.

Serves 6.