Preheat your grill or grill pan to medium-high heat while you prepare the ingredients.
Season the chicken breast with a pinch of salt, black pepper, and garlic powder on both sides.
Drizzle a small amount of olive oil over the chicken to prevent sticking, and squeeze half the lemon over it for a bright flavor.
Grill the chicken breast for about 6-7 minutes on each side or until the internal temperature reaches 165°F. Let it rest for a few minutes before slicing.
Meanwhile, preheat your oven to 425°F. Toss the broccoli florets with a drizzle of olive oil, a squeeze of the remaining lemon juice, salt, and pepper.
Spread the broccoli on a baking sheet and roast in the oven for 15-20 minutes until the edges are slightly crispy.
Prepare the quinoa as per package instructions if not pre-cooked; typically simmer 1/2 cup quinoa in water for about 15 minutes until fluffy.
Plate the dish by serving a portion of quinoa, topping it with sliced grilled chicken, and adding the roasted broccoli on the side. Enjoy your balanced and flavorful lunch!