Basil Pesto Pasta with Grilled Vegetables

Name: Basil Pesto Pasta with Grilled Vegetables
Ingredients: 2 cups fresh basil leaves; ¼ cup grated Parmesan cheese; ¼ cup chopped toasted walnuts; 1 clove garlic, minced; ½ teaspoon salt, divided; ¼ teaspoon ground pepper, divided; ¼ cup extra-virgin olive oil plus 2 Tbsp., divided; 3 portobello mushroom caps, stemmed, gills removed; 2 medium bell peppers (red, orange, and/or yellow), quartered; 1 medium yellow summer squash, trimmed and cut into 1/2-inch-thick planks; 5 scallions, trimmed; 4 ounces whole-wheat penne pasta (1 1/2 cups); 2 cups zucchini noodles (6 oz.); ⅓ cup low-sodium canned cannellini beans, rinsed