Preheat your oven to 425°F and line two large baking sheets with parchment paper to prevent sticking and make cleanup effortless. This temperature matters because anything lower won't caramelize the vegetable edges where the real flavor happens.

Chop your butternut squash into 1-inch cubes, cut carrots into ¼-inch-thick rounds, halve the Brussels sprouts, slice peppers into 1-inch strips, and slice red onion into thin half-moons. Uniform sizing means everything finishes cooking at the same moment instead of some pieces turning soft while others stay firm.

Combine all chopped vegetables in a large mixing bowl and drizzle with olive oil, then sprinkle kosher salt, black pepper, dried thyme, and dried rosemary throughout. Use your hands to toss everything together for a full minute—this feels tedious but ensures every piece gets coated with seasonings, which I learned the hard way after one dry batch.

Divide the mixture evenly between your two prepared baking sheets in a single layer, then slide them into the 425°F oven for 45 to 50 minutes. Resist opening the oven door during the first 30 minutes because the escaping heat can interfere with the caramelization process that develops those deeply satisfying edges.

Stir the vegetables once at the 25-minute mark, rotating the baking sheets from front to back at the same time for even cooking. You'll notice the bottoms turning golden brown on the sheet—this is exactly what you want, not a mistake.

When the vegetables have roasted for the full time, remove both baking sheets and drizzle the maple syrup and apple cider vinegar evenly across the easy fall roasted veg. Toss everything together gently for 30 seconds and taste one piece to confirm the seasoning balance.

Transfer the roasted fall vegetables Thanksgiving style into a large serving dish and let sit for exactly 3 minutes before bringing to the table—this allows flavors to settle and temperatures to distribute evenly throughout.