Preheat grill on medium-high heat. Coat the asparagus with olive oil using your hands. Season with salt and pepper. Coat the grill with olive oil. Spread asparagus across the grill and cook for 3 minutes. Turn the asparagus over and cook for an additional 3 minutes or until asparagus is slightly crunchy, not soft.
Remove from grill and transfer to a platter. Drizzle the balsamic vinegar syrup over the asparagus before serving. Season with additional salt and pepper to taste.
**Balsamic Syrup Instructions: While asparagus is cooking, prepare the balsamic syrup by cooking ½ cup balsamic vinegar on medium heat until it thickens and forms a syrup like consistency, about 3-4 minutes. Be careful not to let it thicken too much or it will turn into black goop.
***To roast the asparagus in the oven, follow the instructions above except cook the asparagus in a preheated 450 degree oven. Cook for 15-20 minutes.