Preheat the oven to 425°F. Toss the potatoes with half the oil, half the seasoning, and give them a 10-minute head start on the sheet pan — they need it.

Toss the sausage coins, peppers, and onion with the remaining oil, Italian seasoning, garlic powder, salt, and pepper.

Add everything to the pan around the potatoes in as close to one layer as you can manage — crowding steams, spreading roasts.

Roast 20 to 25 minutes, stirring once halfway, until the potatoes are tender, the peppers have charred edges, and the sausage is browned.

Shower with parsley and serve straight off the pan — the crispy bits at the edges belong to whoever grabs them first.