Stew the onions in a pan with the olive oil and water over a low heat until the onions soften. At the same time, in a frying pan cook the bacon for 5 minutes until golden. Roll out the short crust pastry until 5 mm thick. Cut out a circle of pastry, slightly larger than the Camembert, then put on a baking tray. Slice the Camembert in half horizontally and place one half on the pastry. Cover the Camembert with the onions and most the bacon, then place the other half camembert, rind down, on top. Mold the pastry around the edge of the cheese, then bake in pre-heated oven at 180°C for 40 minutes or until pastry is cooked. Leave to cool, then place in centre of table to share with friends.