Preheat the oven to 400°F.
Place the chicken breast on a baking sheet lined with parchment paper.
In a small bowl, mix the lemon juice, olive oil, chopped rosemary, and thyme to create a marinade.
Brush the chicken evenly with the lemon-herb marinade, and season with salt and pepper if desired.
Chop the carrot, parsnip, and red onion into uniform pieces and toss them with a splash of olive oil, salt, and pepper.
Arrange the vegetables around the chicken on the baking sheet.
Roast in the oven for about 20-25 minutes until the chicken reaches an internal temperature of 165°F and the vegetables are tender and slightly crispy.
While the chicken and vegetables are roasting, prepare the cooked quinoa if not pre-cooked.
Plate the chicken alongside the roasted vegetables and serve over or with a side of fluffy quinoa.
Garnish with additional fresh herbs and a squeeze of lemon if desired.