This hardly seems a recipe, but perhaps that's what I love best about it. Just the basics, no frills. And it leaves you more time to enjoy the summer evenings.
Toss the asparagus in the olive oil, and season generously with salt and pepper, tossing to evenly coat the vegetables. Drizzle with 1 tablespoon of balsamic vinegar.
Grill the asparagus on high heat for about 6 minutes, until the asparagus are just fork tender, rotating periodically. Transfer to a serving dish and drizzle with a little additional balsamic vinegar.