Step 1

Preheat oven to 425°F.

Step 2

Toss squash and 1 tablespoon oil in a large bowl. Spread out on a large rimmed baking sheet. Roast for 10 minutes.

Step 3

Meanwhile, toss broccoli, bell peppers, onion, Italian seasoning (or herbes de Provence), salt and pepper in the bowl with the remaining 2 tablespoons olive oil until the vegetables are evenly coated.

Step 4

Add the squash to the vegetables in the bowl. Toss to combine. Spread the vegetables out on 2 large rimmed baking sheets, dividing evenly. Roast, stirring once or twice, until the vegetables are tender and browned in spots, 17 to 20 minutes. Drizzle with vinegar.