Preheat your oven to 425°F (220°C).
In a large bowl, combine the asparagus and carrots.
Drizzle the olive oil over the vegetables and sprinkle with garlic powder, dried thyme, salt, and pepper. Toss until the vegetables are evenly coated.
Spread the vegetable mixture in a single layer on a baking sheet.
Roast in the preheated oven for 20-25 minutes, or until the vegetables are tender and slightly caramelized, stirring halfway through for even cooking.
Remove from the oven and drizzle with lemon juice. If desired, sprinkle with grated Parmesan cheese before serving.