Mix it all up until it is a big lump then shape into a sausage and place on a baking tray and cover with the remaining mushrooms.
  
 
 Step 3:

Put this in the oven at 374 degrees Farenheit for 25mins

Now you need some puff pastry. I am not a pastry chef so I went out and bought some frozen rolls of it, defrosted them and use that instead. You can get them in any major supermarket.

Lay them out so you have enough area to cover the entire sausage when it comes out the oven.