The lemony flavor from the zest brightens up this simple vegetable side, without discoloring the stalks the way lemon juice will.
Trim ends of asparagus as desired and place into a large bowl. Drizzle with olive oil, salt and pepper.
Brush the surface of a cast iron grill pan with oil and place over high heat until very hot. Add as many stalks of asparagus as will fit without touching. Let cook without moving for about 1 minute. Turn stalks over and cook the other side another minute. As asparagus becomes tender, remove to a platter. Repeat with remaining asparagus. Keep in mind that if the stalks are thick, they’ll require more cooking time.
Before serving, drizzle the asparagus with a bit more olive oil, and grate the zest of the lemon with a microplane over the top.