Cooked this using bits and bobs on offer at Tesco Express. The sauce is single cream with cheddar cheese.
Recipe’s here except I used a mix of mozzarella and parmesan for the Béchamel sauce and added a bay leaf. And red wine in the photo that I added a splash of into the ragu sauce. I followed the tips here particularly fresh mozzarella (supermarkets sell them in ball form) and adding spinach.