To make the vinaigrette, whisk the oil and verjuice until amalgamated, then add the capers and pepper.

While the asparagus steams, make the vinaigrette.

To make the vinaigrette, squeeze the juice from the other half of the lemon into a small bowl.

Make the vinaigrette by whisking together all the ingredients except the oil until well combined.

- Make the vinaigrette and refrigerate up to 2 days ahead of time.