Prep the vegetables by cutting them into even, bite-sized pieces or thick slices to ensure uniform cooking.
In a small bowl, whisk together the olive oil, lemon juice, minced garlic, chopped parsley, salt, and pepper to create the marinade.
Place the chopped vegetables in a large bowl or zip-top bag and pour the marinade over them. Toss well to coat evenly. Let sit for at least 30 minutes at room temperature.
Preheat your grill to medium-high heat, approximately 400 degrees Fahrenheit.
Place the marinated vegetables on the grill directly or in a grill basket. Cook for 10 to 15 minutes, turning occasionally, until tender and slightly charred.
Remove from the grill and garnish with extra fresh parsley and a squeeze of lemon juice before serving.