Preheat your oven to 200 degrees centigrade
Cut sausage into 1-inch chunks - I like to cut them on an angle with a really sharp knife.
Coat a large tray with a drizzle of oil.
Combine raw sausage pieces, potatoes, peppers, onion and garlic in the tray. Drizzle with olive oil.
Sprinkle with Italian seasoning, salt, pepper, and crushed chilli flakes, if desired.
Spread ingredients out in a single layer.
Bake for 40-45 minutes, or until sausage is fully cooked and vegetables are tender.