Toss the scallions in 2 tablespoons of the olive oil and season with salt and pepper. Grill the scallions until the bulbs are tender and the greens are well charred, 6 to 8 minutes, turning every couple of minutes. Set aside to cool. When the scallions are cooled, chop them finely.
Bring a large pot of salted water to a boil for the pasta. Add the pasta and cook until al dente, about 2 minutes less than the package instructions.
In a medium bowl, whisk together the vinegar and mustard. Season with salt and pepper. Whisk in the remaining 1/3 cup olive oil. Add the scallions and toss to coat.
When the pasta is finished cooking, drain and add to the vinaigrette. Add the olives, tomatoes, red onion, provolone, dill, parsley and arugula. Toss to combine.