Start by preheating your oven to 400ºF and lightly coat a large baking sheet with cooking spray.
Arrange the diced sweet potatoes and halved Brussels sprouts on the sheet, ensuring the Brussels sprouts are placed cut side down for a golden sear.
Drizzle with olive oil, then season with your favorite spices, salt, and pepper. Roast in the oven for 15 minutes.
While the vegetables are roasting, prepare the sauce by mixing maple syrup and Dijon mustard in a bowl.
After 15 minutes, take the baking sheet out of the oven and add sliced sausage, minced garlic, and chopped red onion.
Pour half of the maple-Dijon sauce over the mixture, toss to coat, and spread everything into a single layer on the sheet.
Return the sheet to the oven and roast for another 15 minutes, or until the vegetables are tender.
Once done, remove from the oven and drizzle the remaining sauce over the sausage and vegetables, tossing to coat evenly. Garnish with parsley and serve immediately. Enjoy!