Italian-seasoned chicken breasts roast alongside broccoli, carrots, and red onion on a single sheet pan. Ten minutes of prep, one pan to wash, and a complete dinner in about 40 minutes.
Preheat oven to 400°F. Line a large, rimmed baking sheet with foil.
Combine the Italian seasoning, salt, garlic powder, onion powder, and pepper in a small dish and set aside.
Slice the chicken breasts in half through the center to create two thinner pieces.
Arrange the chicken in the center of the baking sheet. Drizzle with olive oil and rub into both sides to coat. Sprinkle about two-thirds of the seasoning mixture over both sides, rubbing it in.
Arrange the vegetables on either side of the chicken in a single layer. Drizzle with olive oil, toss gently to coat, then sprinkle evenly with the remaining seasoning.
Bake for 25 to 30 minutes, until the vegetables are fork tender and the chicken reaches 165°F at the thickest point.
Tent with foil and rest 5 minutes before slicing and serving.
Notes
Even thickness matters. Slicing thick breasts in half horizontally is what keeps the chicken from drying out before the vegetables finish.
Do not crowd the pan. Use a large rimmed sheet or split across two. Crowded vegetables steam instead of roast.
Kosher salt: The seasoning blend is measured for kosher salt. If using table salt, start with half the amount.
Cut vegetables large. Thick carrot coins and big broccoli florets hold up for the full roast.
For browned chicken: Sear the oiled and seasoned chicken in a hot skillet, 2 minutes per side, then transfer to the sheet pan and bake about 5 minutes less.
Vegetable swaps: Brussels sprouts and green beans can go in from the start. Add zucchini, bell peppers, mushrooms, or cherry tomatoes in the last 12 to 15 minutes.
Adding potatoes: Cut into half-inch pieces, toss with oil and seasoning, and roast 10 minutes before adding the chicken and remaining vegetables.
Chicken thighs: Boneless, skinless thighs work well and need about 5 extra minutes.
Finishing touches: A squeeze of lemon, crumbled feta, or chopped parsley over the finished pan.
Storage: Refrigerate in an airtight container up to 3 to 4 days, or freeze up to 3 months.
Reheating: Microwave gently until warmed through, or spread on a baking sheet and warm at 350°F for 8 to 10 minutes.