Preheat the oven to 400°F (200°C).

Wash and chop the bell peppers, red onion, and zucchini into bite-sized pieces.

In a large mixing bowl, combine the sliced sausage and chopped veggies.

Drizzle olive oil over the mixture and sprinkle with garlic powder, Italian seasoning, salt, and pepper. Toss until well coated.

Spread the sausage and veggie mixture evenly on a large baking sheet.

Place the baking sheet in the preheated oven and roast for 25-30 minutes, stirring halfway through.

Check for doneness: ensure sausage is browned and veggies are tender.

Remove from the oven, let cool for a few minutes, and serve hot.