Preheat your oven to 400°F (200°C).
Cut the spaghetti squash in half, scoop out the seeds, brush the flesh lightly with olive oil, and season with salt and pepper.
Place the squash halves face down on a baking sheet and roast for 35-40 minutes until tender and easily shredded with a fork.
While the squash is roasting, season the chicken breast with minced garlic, mixed herbs, a squeeze of lemon juice, salt, and pepper.
Sear the chicken breast over medium-high heat in a skillet for 2-3 minutes per side, then lower the heat and cover, cooking until the chicken reaches an internal temperature of 165°F (about 8-10 minutes total).
Prepare the quinoa as per package instructions if not already cooked.
Using a fork, gently scrape the roasted spaghetti squash to create strands.
Plate the quinoa, top with shredded spaghetti squash, and add the sliced garlic-herb chicken on top.
Drizzle a little extra lemon juice if desired, and serve warm.