Preheat your oven to 400°F and line a rimmed baking sheet with parchment paper.
Rinse the quinoa under cold water, then combine it with 0.5 cup of water in a small saucepan; bring to a boil, then cover and simmer on low for 15 minutes.
Finely mince the garlic clove and chop the fresh rosemary and thyme leaves.
Place the chicken breast on the baking sheet and rub with half of the olive oil, the minced garlic, chopped herbs, lemon zest, and half of the sea salt and black pepper.
Trim the woody ends off the asparagus and place the spears on the other side of the baking sheet, tossing them with the remaining olive oil, salt, and pepper.
Roast in the oven for 20 to 25 minutes until the chicken is cooked through and the asparagus is vibrant and tender.
Drizzle the fresh lemon juice over the roasted chicken and asparagus immediately after removing from the oven.
Fluff the cooked quinoa with a fork and serve the chicken and vegetables directly on top.