Preheat oven to 400°F (200°C) and line a large rimmed baking sheet with parchment paper.
In a small mixing bowl, whisk together the olive oil, honey, minced garlic, soy sauce, salt, black pepper, and red pepper flakes.
Place the cubed sweet potatoes, chopped bell peppers, and red onion wedges on the prepared baking sheet.
Drizzle half of the honey garlic mixture over the vegetables and toss until evenly coated.
Spread the vegetables into a single layer and roast in the oven for 15 minutes.
Remove the baking sheet from the oven and add the sliced sausages.
Drizzle the remaining honey garlic mixture over the sausages and vegetables, tossing to combine.
Arrange the mixture back into a single layer and roast for an additional 15 to 20 minutes until the sweet potatoes are tender and the sausages are browned.
Remove from the oven and garnish with fresh parsley before serving.