TRIM THE ARTICHOKES. Break off the tough outer leaves and slice off the top 2/3 of the remaining inner leaves. Trim the outsides, cut the artichokes in quarters and remove the chokes. Dice the trimmed hearts into small pieces. Put them in the acidulated water as you work. Keep the garlic cloves whole. Warm the olive oil and add the leeks, drained artichokes, garlic, potato, lettuce or sorrel, parsley and mint. Season with the salt, add 1/2 cup water and stew gently until the vegetables are wilted, about 5 minutes. Add the peas and the rest of the water. Bring to a boil, then lower the heat and simmer, partially covered, for 20 minutes or until the artichokes are cooked. Taste for salt. Puree the soup or leave it as is and serve with the freshly ground pepper, add a few good pinches of chervil or parsley, a spoonful of olive oil drizzled into each soup plate and a dusting of cheese.