Heat some oil in a frying pan over a medium heat and add in the onion and garlic. Cook until they start to soften then take off the heat and leave to one side.
Line an oven tray with baking foil and lay in the bacon rashers. Put tin the oven for around 15mins until they are nice and crispy. Take out and leave to rest on some kitchen towel. Once cooled, crush the bacon up.
In a bowl, add the pork mince, herbs, salt and pepper and onions. Using your hands, combine well and put in the fridge until needed.
Roll out the pastry into a rectangle about 30cm x 20cm, to the thickness of a £1 coin.
Take a third of the sausage mixture and spread it in a line down the middle of the pastry, using your fingers to spread it out evenly. You want a strip about 5-8cm wide and about 1cm thick.
Leaving a small gap either side, lay ⅓ of the grated cheese over the top of the pork. Add the sliced mozzarella along the top of the cheddar, then the bacon pieces, then the jalapeños.
You then need to cover the fillings with the rest of the pork meat. I found the easiest way to do this was to do it a bit at a time. Flatten a ball of meat in the palm of your hand and place on top, Work your way down the roll covering the filling.
Use your fingers to seal the meat all around so that the filling doesn't escape during cooking.
Trim the pastry, then make cuts about 1cm apart from the meat roll to the outside of the pastry. Do this on both sides. Brush a little milk over the side closest to you and pull the pieces of pastry over the meat. Brush the top with a little milk and fold the other side over. Brush the whole wthing with a little milk and pop in the fridge for about half an hour.
Pre-heat the oven to 180º.
When you are ready to cook the roll, sprinkle over the parmesan cheese and a pinch of black pepper. Put in the oven for around 40minutes until golden brown
Notes
Nutritional values are based on one of twelve servings.