Drain the pineapple or mandarin oranges, reserving juice. Stir together half of the pineapple or mandarin juice with the pudding mix until well blended. Gently fold in the whipped topping or cottage cheese and carefully stir in the pineapple or mandarins, marshmallows, and pecans or walnuts. Add additional juice only if needed, this should be moist but not runny. 
Cover and refrigerate at least one hour or preferably overnight.

Serve in individual clear goblets.

Note: Variations, add 3 to 4 bananas, sliced; garnish with shredded sweet coconut and/or Maraschino cherries, drained.