Dissolve jello and salt in boiling water.
Stir in lemon juice. Drain pears,reserving syrup.
Measure syrup,add enough cold water to make 1 1/2 c and stir into jello.
Pour half the jello into bowl and chill until thickened.
Dice pears and fold into thickened jello and spoon mixture into 1 1/2 quart mold.
Chill until set,but not firm.
Chill remaining half of jello mixture until slightly thickened.
In a large bowl,add cream cheese,gradually blend in slightly thickened jello and ginger, beating with a mixer until light and fluffy and thickened.Stir in nuts. Spoon over set jello in mold and chill until firm. Unmold and garnish with salad greens ,if desired.