Fruit filling for japanese fruitcake

2 tb flour
      1    Juice of 3 lemons
      1 c  Sugar
      1 cn Pineapple (20 oz)*
      2    Egg yolks
    1/2 c  Pecans chopped
 
  * - pineapple should be crushed & drained.
  
  Combine all ingredients in top half of a double boiler over, not in,
  simmering water and cook, stirring frequently, until mixture
  thickens. It should be quite thick. Remove from heat and allow to
  cool, stirring occasionally.