Preheat the oven between 400 to 450 degrees F. Line a baking sheet with parchment paper or a silicone mat.
Prepare your vegetables by dicing them into even slices or cubes, or keep them whole. Add them to a mixing bowl and toss with the olive oil and seasonings of choices. Transfer to the baking sheet and spread them out so they don't overlap.
Put the baking sheet on the center rack of the oven. Softer vegetables (zucchini, tomatoes, broccoli, cauliflower, asparagus) need shorter cooking times, 15-25 minutes. Harder vegetables (root veggies, squash, potatoes) need longer cooking times, 25-40 minutes, depending on how thin you slice them.
Check your veggies halfway through the estimated cooking time and stir or flip them with a spatula. Enjoy your veggies warm!
Notes
Nutrition facts will vary depending on the types of vegetables you use.