If using wooden skewers, soak them in water for at least 20 minutes to prevent burning.
In a small mixing bowl, whisk together the olive oil, minced garlic, lemon juice, chopped parsley, dried oregano, sea salt, and black pepper to create the marinade.
Prepare the vegetables by cutting the red bell pepper, zucchini, and red onion into 1-inch thick bite-sized chunks.
Thread the shrimp and vegetable pieces onto the skewers, alternating between them for even cooking and a colorful presentation.
Brush the prepared skewers generously on all sides with the garlic-herb marinade.
Preheat your grill to medium-high heat and lightly grease the grates with a small amount of oil.
Place the skewers on the grill and cook for 3 to 4 minutes per side, or until the shrimp are pink and opaque and the vegetables are tender with light char marks.
Remove the skewers from the grill and serve them hot over the bed of warm cooked quinoa.