Place the stalks in a length of foil, along with the ice cubes, and dash the olive oil and salt over it.
Make a pouch with aluminum foil, making it as airtight as possible. What will happen is that the ice cubes will melt very quickly, turning to water and then to steam, creating a hot steam pouch. Create several folds if you need to in order to ensure that the pouch is as airtight as possible.
Put on the grill on high heat, flipping the pouch after 5 minutes, ensuring you don’t poke any holes in it. Leave on the grill for 5 more minutes.
Remove from the grill and open the pouch up. You will see that not only is our asparagus beautifully steamed through, but also features some gorgeous dark sear marks along one side.