Rub the asparagus in the olive oil so that they are well coated. Divide the asparagus into four equal bunches. Wrap each bunch in a bacon rasher, securing with a wooden skewer if necessary. Place on a roasting tray and season with salt and pepper.
Roast for 10 to 15 minutes in the preheated oven, or until the bacon is crisp and the asparagus is tender.