1. Place the balsamic vinegar in a small saucepan and bring to a boil over high heat. Immediately reduce the heat to simmer and let the vinegar reduce until you have one tablespoonful, 5-7 minutes.

2. While the balsamic vinegar is reducing heat a skillet over medium-high heat. Add the olive oil and asparagus and season with salt and pepper. Turn the asparagus frequently until it is crisp-tender and slightly browned, 3-5 minutes depending on the size of the asparagus and preferred doneness.

3. Add the butter to the skillet, let it melt and toss to coat the asparagus. Drizzle lemon juice over top; taste the asparagus and season with additional salt and pepper if needed.

4. Plate the asparagus and drizzle the balsamic vinegar reduction over the spears. Serve immediately.