Add the sesame seeds to a small frying pan over medium heat. Toast them till they've just taken colour - make sure to watch them carefully and shake the pan every so often as they burn easily. Once they're toasted, set the pan aside.
Place the asparagus in a large frying pan over medium high heat. Add the boiling water straight from the kettle, along with the salt to ensure the asparagus retains its lovely green colour. Cook for 5 to 7 minutes, or until tender.
Remove the asparagus to a serving plate and drain the water from the pan. Add the butter to the pan, over medium heat, and then add the sesame seeds along with some salt and pepper to taste. Drizzle the melted butter mixture over the warm asparagus and enjoy!