Preheat the oven to 400°F.
In a small bowl, combine lemon juice, minced garlic, olive oil, dried thyme, dried rosemary, salt, and pepper to create the marinade.
Place the chicken breast in a baking dish and coat it evenly with the marinade.
Roast the chicken in the preheated oven for 20-25 minutes or until the internal temperature reaches 165°F.
While the chicken is roasting, rinse the quinoa. In a small pot, bring water to a boil, add the quinoa, lower the heat, cover, and simmer until the quinoa is fluffy and water is absorbed, about 15 minutes.
Cut broccoli into florets, toss lightly with salt, pepper, and a small drizzle of olive oil, and roast in the oven (can be added during the last 15 minutes of the chicken roasting) until tender and slightly crispy.
Plate the roasted chicken alongside a serving of fluffy quinoa and roasted broccoli, and enjoy your balanced meal.