Cooking asparagus sous vide locks in flavour that would normally be lost when boiling in water. It also allows for precise cooking and the slightly lower temperature prevents the cells of the vegetables from breaking down too much, keeping the asparagus crisp.
Preheat the water bath to 75°C
Peel the asparagus and trim off the woody ends
Transfer to a vacuum bag with a pinch of salt and a dash of olive oil and seal
Cook for 10–15 minutes depending on the thickness of the spears. You can test if the asparagus is done by gently squeezing the base of a spear – it should give a little but still be firm
If not serving immediately, put the bag into a bowl of iced water for 2–3 minutes to stop the cooking
Try using other fats in the bag such as butter, rapeseed oil or hazelnut oil for extra flavour.