Pre-heat the grill with a grill pan on the grates.
Rinse and pat dry the asparagus. Cut off the tough bottom ends (quick tip – leave that bottom rubber band on and cut above it to make trimming easier).
Monitor while grilling, stirring/flipping occasionally.
Remove from the grill using long-handled tongs and transfer to a serving plate.
Splash with Balsamic Vinegar, and cover with foil to keep the heat in while you plate up your other grilled dinner items.
The 30 minutes of prep time includes bringing the grill up to cooking temperature; actual hands on prep time is less than 5 minutes.
For grilling vegetables, we use a cast iron grill pan, but I've had success with those thinner metal ones with the holes in them that you find in the grilling section of hardware and cooking gadget stores.
Stir occasionally while grilling - these are not fussy and do not need to be perfect; like the grilled mushrooms, the goal is get them good and charred but not burned.