Combine the basil, parsley, walnuts, and cheese in a food processor or mortar. Pulse or grind gradually adding the 3 cups olive oil until the mixture forms a paste.
Bring a large pot of salted water to a boil over high heat. Add the linguine and cook until it is al dente, about 8 minutes; drain and reserve.
Heat 3 tablespoons of oil in a large skillet over high heat. Add the scallops, mushrooms, and zucchini and cook until the vegetables are tender and the scallops are opaque, about 2 minutes. Add a couple of tablespoons of pesto and the linguine. Toss to coat the pasta with sauce. Spoon onto warm plates and serve. Store pesto covered in the refrigerator.
This recipe was provided by professional chefs and has been scaled down from a bulk recipe provided by a restaurant. The Food Network Kitchens chefs have not tested this recipe, in the proportions indicated, and therefore, we cannot make any representation as to the results.