Preparation

• Heat the oven to 450°F. In a large bowl, toss the potatoes with the rosemary, 2 Tbs. of the olive oil, 1 tsp. salt, and a few generous grinds of pepper. Rub the remaining 1 Tbs. olive oil on a heavy-duty rimmed baking sheet. Spread the potatoes on the baking sheet and roast, tossing after 15 minutes, until they’re nicely browned and tender when pierced with a paring knife, about 30 minutes.
• While the potatoes are still hot, toss with 1/2 cup of the pesto, the scallions, and the mint in a large bowl. Transfer to a serving platter, garnish with mint sprigs if you like, and serve warm.