Preheat your oven to 400°F (200°C).

Wash and chop bell peppers, broccoli, zucchini, and red onion into bite-sized pieces and place them in a large mixing bowl.

Slice Italian sausage into bite-sized chunks and add to the bowl with the chopped vegetables.

Drizzle olive oil over the mixture and sprinkle garlic powder, onion powder, paprika, salt, and pepper. Toss until well coated.

Spread the mixture evenly in a single layer on a large sheet pan.

Bake for 30-35 minutes, stirring halfway through, until the sausage is golden-brown and vegetables are tender.

Remove from the oven and sprinkle with fresh parsley before serving.

Serve warm from the sheet pan.