Cut all vegetables into uniform 1-inch pieces—this ensures even cooking and prevents some from becoming mushy while others remain hard. Smash the garlic cloves to release their oils and flavor. Strip the thyme and rosemary leaves from their stems and chop them roughly. In a small bowl, combine the olive oil with the chopped herbs and smashed garlic, stirring well to distribute the aromatics throughout the oil. I like to let this herb oil sit for a few minutes so the flavors start to infuse into the oil before adding it to the vegetables.

Place all the cut vegetables into a Dutch oven, distributing them evenly. Pour the herb oil mixture from Step 1 over the vegetables and toss everything together using a wooden spoon or your hands until the oil and herbs coat all the pieces evenly. Cover the Dutch oven with its lid and place it in a preheated 350°F (180°C) oven. Roast for 1 hour, stirring and turning the vegetables halfway through cooking to ensure even browning and caramelization. The vegetables are done when they're tender when pierced with a fork and the edges have started to brown slightly.

Remove the Dutch oven from the oven and carefully take off the lid—watch out for the hot steam rising from inside. Give the vegetables one final gentle toss to distribute any flavorful bits that may have settled at the bottom. Taste and adjust seasoning with salt and pepper if needed. I find that roasted vegetables are best served while still warm, when they have the best texture and the herb flavors are most vibrant.