Preheat oven 180C.
Heat oil and 40g butter in a saucepan on medium heat add chicken mince and cook mince until it is cooked for about 5 minutes.
Add bacon and cook till browned. In same pan add onion, garlic, zucchini and oregano and cook until all vegetables are tender. Season with salt and pepper. Add breadcrumbs and egg to chicken and veg mix. Mix well.
Set aside to cool.
Make white sauce.
Melt last of the butter and add the flour and mix together with a wooden spoon. Cook for 1 minute.
Turn down temperature and gradually add the milk to the roux. Continue until all the milk is gone and the sauce is nice and smooth. At the last minute add 50g of the parmesan and then set aside.
Fill cannelloni tubes with filling.
Add half of the sauce to the dish and layer with the filled cannelloni tubes and add the rest of the sauce on top and add last of the parmesan cheese on top.
Cook in oven for 30 minutes or until the cheese is melted and slight browning on top.