Preheat your oven to 400°F (200°C) and allow it to fully heat before placing the vegetables inside. This helps create a roasted texture instead of steaming.

Wash all vegetables thoroughly and dry them well. Chop them into similar-sized pieces to ensure even cooking and prevent some pieces from overcooking.

Place all the chopped vegetables onto a large sheet pan. Make sure the pan is big enough so the vegetables are not crowded.

Drizzle olive oil evenly over the vegetables. Sprinkle salt, black pepper, garlic powder, and oregano on top. Toss everything well until all vegetables are evenly coated with oil and seasoning.

Spread the vegetables out into a single layer across the pan. Avoid stacking or overlapping too much, as this can prevent proper roasting.

Place the sheet pan in the oven and roast for 20 to 25 minutes. Halfway through cooking, remove the pan and flip the vegetables using a spatula to ensure even browning.

Continue roasting until the vegetables are tender and slightly crispy on the edges. Remove from the oven and let them cool for a few minutes before serving.