Rinse and drain shrimp and cut each shrimp in half.
In a medium saucepan over low heat, combine gelatin and water. Add bouillon cubes, heat gently (do not bring to a boil) and stir until gelatin and bouillon cubes are dissolved. Remove from heat and cool slightly.
In a bowl of an electric mixer on medium speed, beat cream cheese until smooth. Slowly add gelatin liquid, beating until well combined and mixture is smooth.
Add mayonnaise and tomato paste and beat until well combined. Stir in shrimp, celery, green peppers and green onions.
Pour into a 4-cup mold (or bowl) and refrigerate at least 4 hours, preferably overnight. Unmold (or, if using bowl, retain in bowl) and serve surrounded by decorative greens, crackers or Melba toast.
Nutrition information per serving of 12: