Preheat the grill pan on medium-high heat for 3 minutes or if you use a grill, preheat to medium heat (that's around 370°F or 190°C) and brush the grill grates clean.In the meantime, rinse and trim the woody ends of the asparagus with a sharp knife, or snap ends with your hands.
Transfer to a dish and season with olive oil, salt, and blackpepper. Toss with your hands to coat evenly in oil.
When the grill pan is hot, arrange the asparagus on it and cook for 5 to 10 minutes, depending on how thick the asparagus stalks are. The ones in the picture took exactly 10 minutes. Turn the asparagus with tongs a few times.Tip: if you use a grill, arrange the asparagus perpendicular to the grill bars. You can also use a grill basket to keep them together.
The asparagus are cooked when tender on the inside, with still some bite and with char marks on the surface. To check doneness, poke them with fork. If it slides in easily, the asparagus are ready. They should be fork tender, but not mushy. See notes below for serving suggestions.