I was a chef in the Napa Valley for 20 years.
If I am reading this right, you are talking about the leaves of the plant. Right?
Not the leaves of the artichoke.
I have never tried cooking the leaves of the plant. To be honest, I'm not sure they're edible. I mean, sure you could probably eat them, but are they good? One way to find out.
Now, the leaves of the artichoke are tasty.
I always like to cut the artichoke off with quite a bit of stem left on it. Take the vegetable peeler and give the stem a light peeling. Rub some lemon on it to keep it from oxidizing. I also like to cut them in half and remove the choke. Steam them till tender. I serve em with a lemon-garlic aoli. Basically it's mayo, lemon, crushed garlic, dash of cayenne, salt & pepper.