Preheat your oven to 400°F (200°C) and line a large baking sheet with parchment paper.
Toss the sliced carrots and parsnips on the baking sheet with 0.5 tablespoons of olive oil and a pinch of sea salt.
Roast the vegetables for 15 minutes while you prepare the chicken.
Season the chicken breast evenly with the dried thyme, remaining sea salt, and black pepper.
Heat the remaining 0.5 tablespoons of olive oil in a large oven-safe skillet over medium-high heat.
Sear the chicken for 3-4 minutes per side until a golden-brown crust forms.
Add the halved grapes, minced garlic, and balsamic vinegar to the skillet, swirling to coat the chicken.
Transfer the skillet to the oven (or add chicken to the veggie tray) and roast for another 10 minutes until the chicken reaches an internal temperature of 165°F.
Let the chicken rest for 5 minutes before slicing and serving alongside the caramelized vegetables and grapes.