Preheat your oven to 400°F.
On a large sheet pan, combine the sliced chicken apple sausage, red onion, Brussels sprouts, and sweet potatoes.
Drizzle the olive oil over the mixture and sprinkle with garlic powder, dried thyme, smoked paprika, salt, and pepper. Toss everything together until well coated.
Spread the ingredients in a single layer on the sheet pan.
Roast in the preheated oven for 25-30 minutes, or until the vegetables are tender and the sausage is browned, stirring halfway through for even cooking.
Remove from the oven and let cool for a few minutes. Garnish with fresh parsley before serving.