Toss the corn and tomatoes with olive oil, salt and pepper.
Roast until the corn is golden and the tomatoes are wrinkled.
Place roasted corn, olive oil, garlic, Parmesan, walnuts, salt & pepper in a food processor.
Puree into a thick pesto.
Cook the pasta and then stir in the corn pesto.
Fold in the remaining corn, tomatoes and scallions.