Adjust oven rack to middle position and heat to 450℉.
In a large bowl, add 2 pounds potatoes, 2 tablespoons extra-virgin olive oil, 1½ teaspoons salt, 1 teaspoon pepper, and 1 teaspoon herbes de Provence. Toss until potatoes are well coated.
Arrange potatoes cut side down in a single layer on rimmed baking sheet. Roast for 20 minutes or until potatoes are tender and cut sides are golden brown.
Meanwhile wipe bowl clean with paper towels, add ⅓ cup minced sun-dried tomatoes, ¼ cup finely chopped Kalamata olives, ¼ cup chopped fresh parsley, 3 tablespoons finely chopped shallot, 2 teaspoons grated lemon zest, and 1 tablespoon lemon juice, 1 clove minced garlic, ½ teaspoon red pepper flakes, and remaining 2 tablespoons olive oil. Combine well.
Transfer hot potatoes to tomato mixture. Toss to combine. Let sit for 30 minutes, tossing occasionally.
Transfer to a platter and serve.