To make the pesto, finely chop the garlic, basil, walnuts, parmesan, lemon juice, salt and pepper in a food processor or blender. With the motor running, pour 1/4 cup olive oil through the feeder tube mixing until the pesto is fully combined.
Bring a large pot of salted water to a boil. Cook the pasta until al dente according to package instructions.
While the pasta is cooking, heat 1 tablespoon olive oil in a large skillet over medium high heat. Sauté the tomatoes until they start to wrinkle, about 4-5 minutes.
Then add the corn and the white parts of the scallions. Continue sautéing, stirring frequently, until the corn turns bright yellow and more of the tomatoes wrinkle and some burst, about 3-4 minutes.
Use a slotted spoon to take the pasta straight from the pot to the skillet. Stir the pasta and pesto with the tomatoes and corn.
Then fold in the green parts of the scallions and garnish with additional parmesan as desired.