Herbed Swordfish and Shiitake Kebabs

Name: Herbed Swordfish and Shiitake Kebabs
Ingredients: Vegetable oil, for the grill; 1/2 cup plus 1 tablespoon extra-virgin olive oil; 2 tablespoons chopped fresh parsley; 2 tablespoons chopped fresh cilantro; 2 tablespoons chopped scallions; 2 tablespoons red wine vinegar; 1 clove garlic; 1/4 teaspoon red pepper flakes; Kosher salt; 2 pounds center-cut swordfish, skin removed, cut into 1-to-1 1/2-inch pieces; 1 1/2 teaspoons ground cumin; 1/2 teaspoon ground coriander; 4 ounces shiitake mushrooms, stemmed and halved or quartered if large; 1 red onion, quartered