Preheat the oven to 375 degrees F.
Spread the pine nuts on a sheet pan. Toast in the oven until they turn golden brown, about 5-7 minutes.
In a rectangular baking dish, combine the tomatoes and garlic. Stir in the olive oil, balsamic vinegar, salt and pepper. Roast for 40-45 minutes until the tomatoes have deepened in color and have slightly wrinkled.
While the tomatoes and garlic are roasting, cook the pasta in salted boiling water until al dente according to package instructions. Drain the pasta and rinse in cold water in a colander. Put the pasta in a large bowl.
Use a slotted spoon to transfer the roasted tomatoes to the bowl with the pasta.
In small bowl, squeeze the garlic cloves out of their skins and mash the garlic into the pesto. Stir in the olive oil and the tomato juices from the roasting pan.
Pour the dressing over the pasta and stir in the basil, chives, mozzarella and pine nuts.
Season to taste and add salt and pepper as needed.