To prepare the balsamic reduction: On the stove top, pour the entire bottle of balsamic vinegar into a saucepan and stir in the sugar until it dissolves.
Bring to a boil. Lower the heat to a simmer and reduce the vinegar by 1/2-2/3 in volume.
Set aside to cool slightly. The vinegar should become slightly thicker and intensify in flavor. Makes 3/4 cup
To roast the asparagus: Preheat the oven to 450°F. Line 2 baking sheets with aluminum foil or parchment paper. Spritz with cooking spray.
Clean and remove the woody portion of the asparagus stalks and pat dry with a paper towel. Arrange the asparagus spears on the baking sheets in a single layer.
Drizzle with olive oil, and season with garlic salt and pepper to taste. If you'd like to make this even lighter, spritz with olive oil cooking spray.
Roast baby asparagus at 450°F for 10-12 minutes or until crisp tender. If the asparagus is thicker, roast for 16-18 minutes.
Remove from the oven and allow to cool on the pans for a couple of minutes before serving.
To serve, drizzle with the balsamic reduction and sprinkle with Parmesan-Romano cheese.