1 bunch asparagus, about 1 pound
1/2 teaspoon black pepper
2 tablespoons olive oil or unsalted butter
Zest and juice of one lemon
Sea salt for garnish
Sous vide immersion circulator
Gallon-sized zip-top freezer bags
Fill a pot with water and place your immersion circulator inside. Set your immersion circulator to 180°F and let the water come up to temperature.
Wash the asparagus and, like a bunch of flowers, make a fresh cut on the bottom, eliminating any of the tough, woody ends.
Add the asparagus to a zip-top, gallon-sized plastic freezer bag. Add the black pepper and olive oil; save the salt for after it’s cooked, as the salt will turn this green veggie a little grey. Toss together in the bag to distribute the ingredients.
Add a few heavy soup spoons to the bag to help weigh it down. This will help keep the asparagus submerged, which will ensure that it cooks evenly.
Seal the bag as tightly as possible by using water-displacement method to help press out all the air. Just put the food in the bag and slowly lower it into the water, letting the pressure of the water press the air through the top of the bag. Once the air is out of the bag, seal it just above the water line. You can do this in the pot of water as it heats—just be careful if the water is already steaming!
Once the water has come up to temperature, submerge the bag of asparagus in the pot of water. Make sure the bag is completely submerged (if it floats, remove it from the water and add a few more spoons to weigh it down).
* Check the asparagus after 6 to 7 minutes if it’s pencil thin.
* Check average or thick asparagus after 8 to 10 minutes.
If you’re at all in doubt, pull them out after 8 minutes, open the bag carefully, and use a fork to determine how tender the spears are. If the fork is getting stuck in the asparagus, it’s not ready; reseal the bag and return it to the water for another minute or two.
Remove from the water, turn off the circulator and serve immediately. Sprinkle some lemon juice and zest over the top of the asparagus, along with some of the cooking oil or butter (if desired) and some flaky sea salt, such as Maldon.
Leftover asparagus will keep refrigerated for about 5 days.