Preheat your oven to 400°F (200°C) and heat a grill or grill pan over medium-high heat.
Trim the woody ends off the asparagus and mince the garlic cloves finely.
In a small bowl, whisk together the olive oil, lemon juice, minced garlic, sea salt, black pepper, dried oregano, and red pepper flakes.
Place the chicken breast in a shallow dish and the asparagus on a parchment-lined baking sheet.
Drizzle half of the lemon-herb mixture over the chicken and the remaining half over the asparagus, tossing the asparagus to coat evenly.
Roast the asparagus in the oven for 10-12 minutes until tender and slightly charred.
While the asparagus roasts, grill the chicken breast for 6-7 minutes per side, or until the internal temperature reaches 165°F.
Allow the chicken to rest for 3 minutes before slicing.
Serve the grilled chicken and roasted asparagus over the warm cooked quinoa.