Preheat oven to 400. Line a baking sheet with parchment paper. Spread the potato halves out on the sheet. Drizzle olive oil, then add rosemary, salt and pepper. Toss to fully coat each potato.Roast the potatoes in a preheated oven for 20 minutes, flipping them once halfway through.While the potatoes are in the oven, prepare the rest of your salad. Combine the greens and the olives in a large bowl.As soon as the potatoes are done cooking, transfer them to the bowl with the rest of the salad. The potatoes will make the greens wilt a bit, which I like. If you want to keep the greens crisp, let the potatoes cool for a bit before adding them. Add the lemon juice and toss to fully combine. Serve immediately or chill until ready to serve. Enjoy!