Preheat oven to 400°F. Line a large sheet pan with parchment paper or lightly grease with cooking spray.
In a large bowl, combine sliced sausage, diced potatoes, bell peppers, and red onion.
Drizzle olive oil over the mixture. Add garlic powder, smoked paprika, oregano, basil, salt, and black pepper.
Toss everything together until evenly coated with oil and seasonings.
Spread the mixture in a single layer on the prepared sheet pan, making sure not to overcrowd.
Roast in preheated oven for 30-35 minutes, stirring halfway through, until potatoes are golden and fork-tender.
Remove from oven and let rest for 3-5 minutes. Garnish with fresh parsley if desired.
Serve hot directly from the pan and enjoy!