Cut the chicken breast into 1-inch cubes and place them in a medium mixing bowl.
In a small jar, whisk together the olive oil, lemon juice, dried oregano, garlic powder, sea salt, and black pepper to create the marinade.
Pour the marinade over the chicken cubes and toss to coat evenly, allowing it to marinate for 15 minutes.
Chop the red bell pepper, zucchini, and red onion into 1-inch pieces suitable for skewering.
Thread the marinated chicken and vegetable pieces onto skewers, alternating between the protein and produce for even cooking.
Preheat a grill or cast-iron grill pan over medium-high heat.
Place the skewers on the grill and cook for 10-12 minutes, rotating every few minutes until the chicken is opaque and the vegetables are tender.
Serve the hot skewers over a bed of cooked quinoa for a complete high-protein meal.