Place the pork in a bowl together with the salt, pepper and oregano. 

Then add the mustard and oil. 

Finally add the peppers and the cheese and mix. 

You can already tell how delicious it will be by the smell!!!

Place the mixture in an oven bag. 

Seal it, make a couple of holes on the top with a large fork, place it in a baking pan with no other additions and bake for 2 hours at 200°C. It will let out some juices at first, but by the time it is cooked all will be absorbed...