Preheat Oven: Set your oven to 400°F (200°C).
Prepare Ingredients: Slice chicken sausage into rounds and chop all vegetables into bite-sized, even pieces.
Season: On a large sheet pan, combine sausage and vegetables. Drizzle with olive oil, then sprinkle garlic powder, Italian seasoning, paprika, salt, and pepper. Toss everything to coat evenly.
Arrange on Pan: Spread mixture out in a single layer, making sure not to overcrowd the pan. Use two sheet pans if needed.
Roast: Bake for 20–25 minutes, stirring halfway through, until vegetables are tender and lightly browned.
Serve: Remove from the oven, garnish with Parmesan or parsley if desired, and serve hot.