Step 1Cut the leeks in half lengthwise and rinse well to get rid of grit. Cut off the ends of the dark green parts, leaving all the white parts plus a suggestion of pale green. (Reserve the trimmings for soup stock.)
Step 2Put the leeks in a large pot and cover with water. Bring to a boil, reduce the heat and simmer uncovered for 20 to 30 minutes. Pour off the liquid and reserve. Place the leeks in a bowl.
Step 3The juice is to be drunk (reheated or at room temperature as preferred) every 2 to 3 hours, 1 cup at a time. For meals, or whenever hungry, have some of the leeks themselves, one-half cup at a time. Drizzle with a few drops of extra-virgin olive oil and lemon juice. Season sparingly with salt and pepper. Sprinkle with chopped parsley if you wish.