Roasting vegetables is a straightforward technique, but following these steps will ensure your carrots and potatoes are perfectly cooked – tender on the inside, slightly crispy on the outside, and bursting with herby flavor.

1. Preheat Your Oven and Prepare Baking Sheet: Begin by preheating your oven to 400°F (200°C). This high temperature is crucial for achieving that desirable roasted texture. While the oven preheats, prepare a large baking sheet. Line it with parchment paper for easy cleanup, or simply grease it lightly with olive oil to prevent sticking. Using a large baking sheet is important to avoid overcrowding the vegetables, which can lead to steaming instead of roasting.
2. Prepare the Vegetables: Wash and peel your carrots and potatoes. For even cooking, cut them into roughly 1-inch pieces. Uniformity in size is key to ensure that all the vegetables cook at the same rate. If using larger potatoes, you may need to cut them into smaller pieces. If using baby carrots, you can halve or quarter them lengthwise depending on their size.
3. Combine Vegetables and Aromatics: In a large bowl, combine the cut carrots and potatoes. Add the minced garlic, chopped fresh rosemary, and chopped fresh thyme. The bowl should be large enough to allow you to easily toss the vegetables without spilling.
4. Drizzle with Olive Oil and Season: Drizzle the olive oil over the vegetables and herbs. Use your hands or a spatula to toss everything together thoroughly, ensuring that the vegetables are evenly coated with oil and herbs. Season generously with salt and freshly ground black pepper. If you desire a touch of heat, add the optional red pepper flakes at this stage. Proper seasoning at this point is vital for bringing out the best flavors.
5. Arrange Vegetables on Baking Sheet: Spread the seasoned vegetables in a single layer on the prepared baking sheet. It’s crucial to avoid overcrowding the pan. Overcrowding will cause the vegetables to steam rather than roast, resulting in a softer, less caramelized texture. If necessary, use two baking sheets to ensure a single layer.
6. Roast in the Oven: Place the baking sheet in the preheated oven and roast for 30-40 minutes, or until the vegetables are tender when pierced with a fork and lightly browned. The roasting time may vary slightly depending on the size of your vegetable pieces and your oven.
7. Flip and Continue Roasting (Optional): For more even browning, you can flip the vegetables halfway through the roasting time, around 20 minutes. This ensures that all sides of the vegetables get exposed to the heat and develop a nice golden-brown color.
8. Check for Doneness: After 30 minutes, check the vegetables for doneness. Pierce a carrot and a potato with a fork. They should be easily pierced and tender all the way through. If they are still firm, continue roasting for another 5-10 minutes, checking again periodically.
9. Crisp Up (Optional): If you prefer your roasted vegetables extra crispy, you can increase the oven temperature to 425°F (220°C) for the last 5-10 minutes of roasting. Keep a close eye on them to prevent burning.
10. Garnish and Serve: Once the vegetables are perfectly roasted, remove them from the oven. If using, sprinkle with fresh parsley for garnish. Serve immediately while hot and enjoy the delicious flavors of your herb-roasted carrots and potatoes!