In a small bowl, whisk together the olive oil, lemon juice, lemon zest, minced garlic, dried oregano, sea salt, and black pepper to create a marinade.
Place the chicken breast in a shallow dish and pour half of the marinade over it, ensuring the meat is thoroughly coated.
Toss the sliced bell peppers and zucchini with the remaining half of the marinade in a separate bowl.
Preheat a grill or grill pan over medium-high heat until hot.
Grill the chicken for approximately 6-7 minutes per side or until the internal temperature reaches 165°F.
Place the vegetables on the grill and cook for 4-5 minutes until they are tender and show beautiful char marks.
Remove the chicken from the heat and let it rest for 3 minutes before slicing into strips.
Assemble the bowl by placing the cooked quinoa at the base, then topping it with the sliced grilled chicken and charred vegetables.