Preheat your oven to 400°F (200°C).

In a large bowl, combine sliced sausage, bell peppers, zucchini, red onion, cherry tomatoes, olive oil, minced garlic, fresh rosemary, salt, and pepper.

Spread the mixture into one even layer on a rimmed baking sheet.

Bake for 25–30 minutes, tossing halfway through.

Remove from the oven and let it rest for 5 minutes.

Use tongs to transfer the sausage and veggies to a serving platter and enjoy.