Start by mixing the sauce ingredients until well blended and place in the refrigerator. That will allow the garlic oils to infuse the mixture.
Preheat a large cast iron skillet to medium high and allow the pan to become very hot.
Meanwhile, remove the tough bases of the asparagus, if necessary, then toss in the olive oil, salt and cracked pepper until all the spears are well coated.
Cook the asparagus in the hot skillet, spreading them in a single layer, if possible.
Leave the spears on one side long enough so that they develop a slight sear, then toss to sear the other side. Cook to preferred tenderness.
Remove from flame and serve hot drizzled with the maple mustard sauce.