Preheat your oven to 400°F and line a baking sheet with parchment paper.
Toss the broccoli florets with 1 teaspoon of olive oil, salt, and pepper, then spread them in a single layer on the baking sheet.
Roast the broccoli for 15-20 minutes until the edges are slightly charred and tender.
While the broccoli roasts, season the chicken breast with the remaining 0.5 teaspoon of olive oil, garlic powder, lemon juice, salt, and pepper.
Heat a grill pan or outdoor grill over medium-high heat and cook the chicken for 6-7 minutes per side, or until the internal temperature reaches 165°F.
If the quinoa is not already cooked, prepare it according to package directions using water or low-sodium vegetable broth.
Let the chicken rest for 5 minutes before slicing it into strips.
Assemble the lunch by placing the fluffy quinoa in a bowl, topping it with the sliced chicken, and serving the roasted broccoli on the side.