Preheat your oven to 400°F (200°C) and line a large rimmed baking sheet with parchment paper.
Peel and slice the carrots into 1/2-inch thick coins and chop the celery into 1/2-inch thick pieces.
Mince the garlic clove finely.
Place the chicken breast, carrots, and celery on the baking sheet.
Drizzle the olive oil over the chicken and vegetables, then sprinkle with minced garlic, sea salt, black pepper, and dried thyme.
Toss the vegetables to coat evenly and flip the chicken to ensure it is seasoned on both sides.
Arrange everything in a single layer, ensuring the chicken is not covered by the vegetables.
Roast in the oven for 20-25 minutes, or until the chicken reaches an internal temperature of 165°F and the vegetables are tender.
Remove from the oven and let the chicken rest for 5 minutes before slicing to keep it juicy.
Serve the sliced chicken alongside the roasted garden vegetables.