Preheat your oven to 425°F (220°C) and line a large baking sheet with parchment paper to prevent sticking and make cleanup easier later. A properly heated oven is important because high heat helps the vegetables roast instead of steam, giving the potatoes crispy golden edges and helping the vegetables caramelize beautifully.

Wash all the vegetables thoroughly under cool running water to remove any dirt or residue. Once cleaned, dry them very well with a kitchen towel or paper towels. Removing excess moisture helps the vegetables roast properly and prevents them from becoming soggy in the oven.

Cut the baby potatoes in half so they cook evenly and develop crispy roasted surfaces. Chop the red and yellow bell peppers into medium-sized chunks, roughly the same size for even cooking. Slice the zucchini into thick rounds so it stays tender without becoming mushy, and chop the red onion into wedges or chunky pieces that will soften and caramelize while roasting.

Transfer all the prepared vegetables into a large mixing bowl with enough space to toss everything comfortably without spilling. Keeping the vegetables together in one bowl helps distribute the seasonings more evenly.

Drizzle the olive oil evenly over the vegetables, making sure everything gets lightly coated. Sprinkle in the garlic powder, dried thyme, rosemary, oregano, salt, and black pepper. The olive oil helps the vegetables roast and caramelize while the herbs and garlic create a warm, savory flavor throughout the dish.

Toss the vegetables thoroughly using a large spoon or clean hands until every piece is evenly coated with oil and seasonings. Take an extra moment here to make sure the herbs and spices are well distributed so every bite tastes flavorful and balanced.

Spread the seasoned vegetables onto the prepared baking sheet in a single even layer. Avoid overcrowding the pan because tightly packed vegetables trap moisture and steam instead of roasting. If necessary, use two baking sheets so the vegetables have enough room to crisp up properly.

Place the baking sheet into the preheated oven and roast for 30–40 minutes. About halfway through cooking, gently stir or flip the vegetables using a spatula to help them cook evenly and develop color on multiple sides. As they roast, the potatoes will become golden and crispy while the onions and peppers turn soft and slightly caramelized.

Continue roasting until the potatoes are fork-tender with crispy edges and the vegetables are beautifully roasted and lightly browned. If you prefer extra crispy potatoes, allow them to roast for an additional 5 minutes while keeping an eye on the vegetables so they don’t overcook.

Remove the baking sheet from the oven and let the vegetables rest for a minute or two before serving. Sprinkle freshly chopped parsley over the top for a fresh burst of flavor and color. Serve warm as a comforting healthy side dish, easy meal-prep option, or nourishing anti-inflammatory dinner.