Whisk together the vinegar, mustard, salt and pepper in a small bowl until combined. Slowly whisk
in the olive oil until emulsified and stir in the peppercorns. Let the vinaigrette
sit at room temperature for 15 minutes before serving. Vinaigrette can be made up to 8 hours in advance and refrigerated.
Heat the grill to high.
with the canola oil and season with salt and pepper. Grill
until tender, about 5 to 7 minutes.
Place grilled asparagus on a platter and drizzle
the vinaigrette over the top.