In a small bowl, whisk together half the olive oil, lemon juice, and dried oregano.
Place the chicken breast in a shallow dish and coat with the marinade, letting it sit for at least 15 minutes.
Preheat your oven to 400°F and line a baking sheet with parchment paper.
Toss the broccoli florets with the remaining olive oil and a pinch of salt, then spread them in a single layer on the baking sheet.
Roast the broccoli for 15 to 20 minutes until the edges are crispy and browned.
While the broccoli roasts, heat a grill or grill pan over medium-high heat.
Grill the chicken for 6 to 7 minutes per side or until the internal temperature reaches 165°F.
Let the chicken rest for 5 minutes before slicing.
In a bowl, combine the cooked quinoa with fresh herbs of your choice.
Serve the sliced chicken over the quinoa salad with the roasted broccoli on the side.