Start by heating your oven to 425 degrees Fahrenheit so it's fully hot when the chicken goes in. Line your baking sheet with heavy-duty foil for easy cleanup later. This high heat is what gives the chicken skin that golden, slightly crisp finish.
Place the chicken pieces on the lined pan and brush them with half the olive oil. In a small bowl, mix the dried basil, rosemary, and garlic salt together, then rub half of this blend over the chicken. This first layer of seasoning is what builds the base flavor into the meat itself.
In the same bowl you used for the herbs, combine the remaining olive oil, quartered potatoes, baby carrots, and onion wedges with the leftover herb mixture. Stir everything together so each piece gets an even coating. This step ensures the vegetables roast with the same flavor as the chicken.
Scatter the seasoned vegetables around the chicken pieces on the baking sheet, giving everything a little breathing room. Crowding the pan traps steam and keeps things from browning properly. Spacing it out is what gives you that roasted, slightly caramelized edge on the veggies.
Slide the pan into the oven and roast for about 45 to 55 minutes, turning the vegetables once halfway through. The chicken is done when a thermometer inserted into the thickest part reads 165 degrees Fahrenheit. The skin should look deeply golden and the potatoes fork-tender by this point.
Once out of the oven, let the tray sit for about 5 minutes before serving. This short rest lets the juices settle back into the chicken instead of running out when you cut into it. It also gives the vegetables a moment to firm up slightly for easier serving.