The cardoon stalks are edible, so remove the green leaves. It's surprisingly easy to remove them by holding the base firmly, then striping off the leaves.
Wear gloves to avoid staining your hands and use only the middle part of the stalks. Fill a bowl with water, squeeze in the lemon, also adding the lemon rinds.
The photo shows the discarded portion of the leaves and fiber. To remove the fiber, shave the flesh with a knife leaving 8 cm of the outer flesh, then pull up to easily remove the fiber.
Place the stalks, the salt, and the lemon water with the lemon rinds into a pot with plenty of water. Boil until tender. The boiling time should be a little less than an hour (about 40 minutes at the least).
Drain, then let cool. Taste and if they are still fibrous, then return them to the pot. They are ready for using in other dishes.
Story Behind this Recipe
No matter how plentiful they grew, I used to consider them only as ornamental plants, but now I am finally cooking with them. Now I'm used to preparing them quickly, so I have more time to think about using them in various recipes.
Don't cut through the stalks completely when making the shallow cuts. Pull the the skin back and forth from the cut. Addendum: The boiling time will vary according to the maturity of the cardoons. The stalks with big leaves may take about 2-3 hours to cook. They will be very tender after boiling for 3 hours.