Preheat the oven to 400 degrees F. Line 2 sheet pans with parchment paper.
In a glass baking dish, toss quartered tomatoes with olive oil, salt and pepper. Arrange in a single layer. On the other sheet pan, toss the potatoes with the remaining olive oil, salt and
pepper, and place cut-side down.
Roast for 20-25 minutes until the tomatoes have let loose some of their water and are looking golden to a bit charred. Continue roasting the potatoes for an additional 20-25 minutes until they are golden brown and tender when pierced with a paring knife.
In a large bowl, toss the potatoes with the pesto, and gently fold in the tomatoes and chives.