1-Trim the stem and end off the: Trim the stem and end off the zucchini. Slice lengthwise into ½-inch thick pieces. Alternatively, cut into diagonal pieces. Place on a sheet tray.
2-In a small bowl, combine salt, Italian: In a small bowl, combine salt, Italian seasoning, black pepper, garlic powder, and onion powder.
3-Brush both sides of the sliced zucchini: Brush both sides of the sliced zucchini with olive oil. Evenly season both sides with the salt mixture.
4-Preheat the grill or grill pan over: Preheat the grill or grill pan over medium heat between 350 and 375°F (160 to 177°C). Clean the grates and grease with olive oil. Place the zucchini slices at a 45-degree angle to the grates. This will give a nice char mark pattern and prevent the pieces from falling through the grates. Lightly press down to make contact with the grates. Cover and cook until golden brown lines form, about 4 to 5 minutes. Flip, cover, and cook until tender but not mushy, about 3 to 5 minutes.
5-Transfer the pieces to a serving dish: Transfer the pieces to a serving dish and garnish with chopped parsley and parmesan cheese (if using).