Preheat oven to 425°F. Line a large baking sheet with parchment paper.
Season vegetables:
Add sweet potatoes, brussels sprouts, and red onion to the sheet pan. Drizzle with olive oil, balsamic vinegar, and maple syrup. Sprinkle with salt and pepper. Toss well to coat and spread into an even layer.
Roast:
Bake for 20 minutes.
Add sausage:
Remove from oven, add sliced chicken sausage, and toss lightly. Return to oven and bake another 15 minutes, until vegetables are tender and slightly caramelized.
Make the sauce:
In a small bowl, whisk together tahini, maple syrup, apple cider vinegar, and warm water until smooth. Add salt and pepper to taste. Adjust thickness with additional water if needed.
Finish & serve:
Drizzle maple tahini sauce over the sheet pan. Top with crumbled goat cheese and chopped parsley