Preheat your grill or grill pan over medium-high heat.
Season the chicken breast with your favorite seasonings (such as salt, pepper, and a squeeze of lemon) and lightly brush with a small amount of olive oil if desired.
Grill the chicken for 6-7 minutes per side or until the internal temperature reaches 165°F. Allow to rest briefly before slicing.
While the chicken is grilling, rinse the quinoa under cold water. In a small saucepan, combine the 1/4 cup of dry quinoa with water (using a ratio of about 1:2), bring to a boil, then reduce the heat, cover, and simmer until the water is absorbed (about 15 minutes). Fluff with a fork.
Preheat your oven to 425°F for the broccoli. Toss the broccoli florets with olive oil, a pinch of salt, and pepper, then spread them out on a baking sheet.
Roast the broccoli in the oven for about 15-20 minutes, until the edges are crisp and the florets are tender.
Plate the sliced grilled chicken over a serving of cooked quinoa, and place the roasted broccoli on the side. Enjoy your balanced, nutrient-packed lunch!