Chicken and Mustard Puff Pockets

Name: Chicken and Mustard Puff Pockets
Ingredients: 500ml Chicken/Vegetable stock; 1 Chicken breast, whole; 100g Bacon bits; 1 teaspoon Butter; 50g Onion, chopped (about half a medium onion); 60g Creme Fraiche or Greek Yoghurt; 60g Smeerkaas or Philadelphia cheese; 2 tablespoons Wholegrain mustard; 4 teaspoons Cornflour/flour (mixed with 4 - 6 tablespoons of water); 500g plain cooked rice (leftovers work great); 20g chopped parsley; 10 sheets of puff pasty (12X12cm sheets); 1 egg, lightly beaten to baste pockets