Preheat oven to 400 deg F.
Line a baking pan with parchment paper or tin foil.
Wash and chop into 1.5” pieces 1.5 lbs. potatoes. Peel and chop into 1.5” pieces 1 large onion. Peel 1 head garlic and slice garlic bulbs into 1/4”-thick slices.
Toss the vegetables in a medium mixing bowl with 3 TB maple syrup, 1 TB balsamic vinegar, 1 TB dried or fresh rosemary, 1 tsp. coarsely ground black pepper, and 1/2 tsp. salt.
Place vegetables onto prepared baking pan.
Bake 30-35 minutes, until vegetables are soft, stirring and turning once, about half-way through.