Cook your pasta according to the package instructions. Drain then rinse with cold water to stop it from cooking and set aside.
Heat up your grill on medium heat for at least 15 minutes.
Add eggplant rounds to a sheet pan. Use the ¼ cup of olive oil to brush onto one side of each round and sprinkle with about ½ teaspoon salt. Flip the eggplant over and repeat with the remaining oil and ½ teaspoon more salt. Arrange them on one side of the grill. Cover and let cook for about 5 minutes, or until you have nice grill marks. Flip and cook 5-10 minutes more, or until you have nice grill marks. Transfer the eggplant to a large bowl and cover with a lid or tinfoil for at least 15 minutes (this will help the eggplant get nice and tender).
Place zucchini and bell pepper on the sheet pan and toss/rub with 1 tablespoon oil and ½ teaspoon salt to coat all over. Transfer cut-side-down to the other side of the grill. Cover and let cook for about 10-15 minutes, or until charred and tender, flipping halfway through.
Transfer the veggies back to the sheet pan and let cool. If bell pepper skins are super burnt, just peel them off. Cut eggplant, zucchini, and bell pepper up into bite-sized pieces and add to the large bowl along with the pasta. Add remaining 2 tablespoons oil, remaining ¾ teaspoon salt, balsamic, lemon, black pepper, herbs, and cheese. Toss to coat. Taste and add more salt, lemon, or balsamic if you think it needs something.
Serve topped with nuts and any remaining herbs or cheese you have leftover (if desired).