Completely dissolve gelatin and salt in boiling water. Add lemon juice. Combine cold water and ice cubes to make 1 1/4 cups. Add to gelatin, stirring until slightly thickened. If necessary, remove unmelted ice cubes. Blend in sour cream; add remaining ingredients. Pour into individual dishes or bowl and chill until set, at least 30 minutes. Spoon from bowl onto lettuce leaves. Garnish with thinly sliced cucumbers, if desired.
|