In a saucepan, add 1 cup of water and blanch the artichoke hearts. Remove them and set aside. Repeat the process with the green peas.
In a large bowl mix the oil with the salt, ginger, saffron, garlic, and lemon. Add the lamb and coat it with the oil and spice mix. Place in a large saucepan, add remaining water, cover and cook at medium heat for 30-40 minutes.
When the meat is tender, add the artichokes, then the sweet peas and cook for an additional 15 minutes.
Notes
Note: If you don't own a tagine, you can always use a slow cooker, Dutch oven or pot.