Preheat your oven to 400°F (200°C) and line a large sheet pan with parchment paper.
Peel and dice the sweet potatoes into 1-inch cubes, and chop the broccoli and carrots into bite-sized pieces.
Place the chicken breast, sweet potatoes, broccoli, and carrots onto the prepared sheet pan.
Drizzle 2 tablespoons of olive oil over the chicken and vegetables, then sprinkle evenly with sea salt, black pepper, rosemary, and thyme.
Toss the vegetables to coat and ensure the chicken is well-seasoned on both sides.
Roast in the oven for 25 to 30 minutes, or until the chicken reaches an internal temperature of 165°F and the sweet potatoes are fork-tender and slightly caramelized.
While the meal roasts, ensure your quinoa is warm and ready for serving.
In a small bowl, whisk together the remaining 1 tablespoon of olive oil and the lemon juice to create a light dressing.
Slice the roasted chicken and the fresh avocado.
Assemble the meal by placing the quinoa in a large bowl, topping it with the roasted chicken and vegetables, and finishing with the avocado slices and a drizzle of the lemon dressing.