Preheat the oven to 400°F (200°C) and line a large rimmed baking sheet with parchment paper.
In a large mixing bowl, combine the sliced sausage, cubed potatoes, diced onion, and chopped bell pepper.
Drizzle the mixture with olive oil and sprinkle with garlic powder, dried oregano, smoked paprika, salt, and black pepper.
Toss the ingredients thoroughly until all components are evenly coated with oil and seasoning.
Spread the mixture across the prepared baking sheet in a single, even layer to ensure proper roasting.
Bake for 40 to 45 minutes, using a spatula to turn the mixture halfway through the cooking time.
Remove from the oven once the potatoes are fork-tender and the sausage is browned.
Garnish with fresh parsley and serve immediately.