Put peas in a steamer basket. Place peas in boiling water and remove immediately. Place in ice water and refrigerate. Combine cream cheese, horseradish, pepper,and onion in a small bowl. Stir until smooth. Chill for 1 hour. Using a sharp knife, slit the snap pea along it's inside length. Spoon mixture into a pastry bag with a decorative tip. Pipe approximately 1&1/2 tsps of mixture into each pod. Sprinkle with chopped bacon. cover and refrigerate until ready to serve.