Parboil the pasta in salted boiling water for approximately 5 minutes. Drain and place the pasta shells on a cloth to cool down.
Add the pork mince to a large frying pan with 2 tbsp of the olive oil and fry over a medium heat for a couple of minutes, until browned and all the water has evaporated. Season with salt and pepper and allow to cool.
Once the pork has cooled down add half of the cold béchamel sauce and stir.
Place the 2 tins of chopped tomatoes on the bottom of a round baking dish. Add 2 tbsp of olive oil, salt and pepper and stir in the remaining half of béchamel sauce.
Using a tablespoon, fill the conchiglioni shells with the pork filling and gently place on top of the sauce in the baking dish, making sure each shell isn’t too close together. Do this until the dish is full.
Cover with silver foil and bake in a pre-heated oven at 180c for approximately 25-40 minutes. 15 minutes before the end put the pecorino cheese on top of the pasta and pork and put back in the oven.