Preheat your oven to 400°F and line a baking sheet with parchment paper.
Toss the broccoli florets on the baking sheet with one teaspoon of olive oil, minced garlic, salt, and pepper.
Roast the broccoli for fifteen to twenty minutes until the edges are tender and slightly charred.
While the broccoli roasts, whisk together the lemon juice, dried oregano, and a pinch of salt in a small bowl.
Brush the chicken breast with the lemon-herb mixture on both sides.
Heat the remaining teaspoon of olive oil in a grill pan or cast-iron skillet over medium-high heat.
Grill the chicken for six to seven minutes per side or until the internal temperature reaches 165°F and the juices run clear.
Let the chicken rest for three minutes before slicing.
Fluff the cooked quinoa with a fork and place it in a bowl.
Top the quinoa with the sliced grilled chicken and serve alongside the roasted garlic broccoli.