Preheat your oven to 425°F. Grab your largest sheet pan—you’re going to want the space.
Toss the butternut squash, Brussels sprouts, apple slices, and onion on the pan. Drizzle with olive oil and sprinkle with thyme, garlic powder, salt, and pepper. Use your hands to get everything nicely coated.
Nestle the sliced chicken sausage in between the veggies. You want them cozy but not crowded.
Roast in the oven for 25–30 minutes, flipping everything halfway through so nothing gets too dark on one side.
Check that your veggies are fork-tender and caramelized. That’s your sign to pull it out. Serve hot, maybe over rice or quinoa if you're feeling fancy, or just eat it straight off the pan like I sometimes do.