Preheat your oven to 400°F (200°C) and line a large baking sheet with parchment paper.
Slice the carrots into 1/2-inch thick rounds or diagonal coins for even cooking.
In a small bowl, whisk together the olive oil, maple syrup, sea salt, black pepper, and garlic powder.
Place the chicken breast on one side of the baking sheet and season with a pinch of salt and pepper.
Toss the carrots in the maple mixture until well coated and spread them in a single layer on the other side of the baking sheet.
Roast for 20-25 minutes, or until the chicken reaches an internal temperature of 165°F and the carrots are fork-tender.
During the last 5 minutes of roasting, sprinkle the chopped pecans over the carrots to toast them slightly.
Remove from the oven, garnish with fresh thyme leaves, and serve immediately.