Preheat your outdoor grill or indoor grill pan to medium-high heat and preheat the oven to 400°F.
In a small mixing bowl, whisk together 0.5 tbsp of the olive oil, lemon juice, lemon zest, minced garlic, rosemary, thyme, sea salt, and black pepper to create the marinade.
Place the chicken breast in a shallow dish and coat thoroughly with half of the prepared lemon-herb marinade, allowing it to sit for 5-10 minutes.
On a parchment-lined baking sheet, toss the asparagus spears with the remaining 0.5 tbsp of olive oil and a small pinch of extra salt.
Roast the asparagus in the oven for 12-15 minutes until the tips are slightly charred and the stalks are tender.
While the asparagus roasts, place the chicken on the hot grill and cook for approximately 6-7 minutes per side, or until the internal temperature reaches 165°F.
Transfer the grilled chicken to a cutting board and let it rest for 3-5 minutes to lock in the juices before slicing into strips.
Plate the sliced chicken over the warm cooked quinoa and serve the roasted asparagus alongside for a complete, clean-eating meal.