If needed, wash your artichoke by placing upside down (petals down) in a bowl of warm salt water for 10-15 minutes, to ensure no insects have hidden in the leaves.
Prepare a large stock pot with water, and add the juice of your lemon. Throw the lemon halves in the water, along with your salt. Bring to a boil.
While your water is heating, trim your artichokes, cutting off the top pointy ends of each leaf with a pair of kitchen shears until you reach near the top - then use a knife to slice off the very top of the artichoke.
Once your water is boiling, turn down to medium heat and add your artichokes, stem side down, into the pot. Cover partially and steam for 30-40 minutes. a leaf pulled out should come out easily when it is fully cooked.
Drain your artichokes and allow to cool for 10-15 minutes if serving warm, or can be cooled to room temperature or in the fridge.