To prepare asparagus, gather and prep all ingredients, oil or spray a baking dish and prepare an ice bath. Boil a pot of salted water and blanch the asparagus for 10-15 seconds until bright green; quickly transfer to the ice bath to preserve color and avoid discoloration.
After removing from the ice bath, pat the asparagus dry with a clean kitchen towel or paper towel. Divide the asparagus into eight even bundles and wrap each bundle with prosciutto, then place in the prepared baking dish.
Sprinkle Gruyere cheese over the asparagus bundles, making sure to leave the tips visible for an appealing presentation.
Bake the asparagus bundles until the cheese is melted and bubbly, then sprinkle with chopped fresh parsley to complete the dish.
Enjoy your delicious and easy-to-make Asparagus Cordon Bleu, a perfect spring side dish that can be prepared ahead of time and is sure to impress your guests!