Preheat the oven to 200°C (400°F) and line a baking sheet with parchment paper.

Toss the sliced carrots with olive oil, salt, and black pepper, and arrange them in a single layer on the baking sheet.

Roast the carrots for 20-25 minutes, or until tender and slightly caramelized.

While the carrots are roasting, whisk together the orange juice, maple syrup or honey, and lemon zest in a small saucepan.

Simmer over low heat for 5-7 minutes, until the sauce thickens slightly.

Drizzle the orange sauce over the roasted carrots and toss gently to coat.

Garnish with fresh parsley if desired and serve warm.