Preheat and Prep: Heat your oven to 400°F (200°C). Line a large, rimmed baking sheet with parchment paper or a silicone mat for easy cleanup and to prevent sticking.
The Flavor Toss: In a large mixing bowl, combine the cubed potatoes, carrots, and zucchini. Drizzle with the olive oil and add the minced garlic, oregano, thyme, salt, and pepper. Toss thoroughly until every piece is evenly coated.
Arrange for Success: Spread the vegetables onto your prepared sheet pan. Crucial Tip: Ensure they are in a single layer with space between them; overcrowding will cause them to steam rather than crisp.
The Roast: Place the pan in the center rack of the oven. Roast for 35–45 minutes. At the halfway mark (around 20 minutes), use a spatula to toss the vegetables to ensure even browning.
Test for Doneness: The vegetables are ready when the potatoes are fork-tender and golden, and the zucchini edges have a light caramelization.
The Finishing Touch: Remove from the oven and immediately sprinkle with the fresh chopped parsley. Serve warm.