Trim the stems of the spinach, and wash it in several waters. Lift it from the water, letting it drain a moment in your hands, and toss it into a large pot. Cover the pot tightly and cook the spinach over low heat for 5 minutes. The leaves should wilt but retain their color and shape. Uncover and raise the heat to boil away all the water. Chop the spinach coarsely, just enough so that the leaves are manageable on a fork. Add salt and pepper, a little sour cream; and a few drops of lemon juice.