Cut each slice of prosciutto vertically for 24 pieces in total. You will be using 2 pieces per asparagus spear.

Gently wash and dry the asparagus spears. Trim off the tough woody ends.

Using 2 strips of prosciutto per asparagus spear, tightly wrap each spear with one strip at a time (going around a few times) leaving both the tips and ends of the asparagus exposed. 

Place asparagus spears and lemon halves on a plate. Drizzle asparagus with olive oil and sprinkle with black pepper. Also, drizzle the cut lemon halves with olive oil. Note there is no salt in this recipe by design as the prosciutto itself is very salty.

Preheat the BBQ grill to medium-high. Arrange the asparagus crosswise on the grill (so they won’t fall through the grates) and place the lemons cut side down on the grill. Grill for a total of 7 - 9 minutes turning often until the asparagus is tender, the prosciutto crisps and the lemons charred. The total grilling time will depend on how thick the asparagus spears are.

Transfer grilled asparagus and lemons to a platter. Squeeze some lemon juice from the charred lemons over the asparagus. Serve warm or at room temperature.

Oven Broiling Method: Preheat the oven broiler to high. Place an oven rack on the top third rungs of the oven. Transfer the spears to a foil-lined baking sheet and broil for 6 – 8 minutes, turning once, until the asparagus is tender and the prosciutto is crisp. Keep your eye on them while broiling.