Preheat oven to 180c and put potatoes unpeeled on tray with rock salt, cook until completely tender all the way through (approx 90minutes)
Place pan over medium heat and add bacon while pan is still cold. Allow to cool, then mix with minced pork, breadcrumbs and season with salt/pepper
On a flat surface place 1 topside steak at a time, then place a reasonable amount of filling in the middle. Roll each topside steak up with filling in the middle.
Now take some of your soaked caul fat and cut a piece that will fit around the parcels, with a small amount of overlap. Neatly wrap all parcels in caul fat, then secure each parcel with a small piece of butcher twine.
To cook, heat the dripping in a cooking pot over a medium, heat and brown the shallots face side down until dark brown/lightly charred. Remove from pan and then brown off the beef olives. Once done add shallots and baby carrots, then add the beef stock, wine, thyme and bay leaf.
Cook gently, either on the hob or in the oven (preheated to 170c), for 21/2-3 hours until tender.
For mash, once potatoes have finished cooking remove from oven and allow to cook enough that you can handle them. Cut them in half and scoop out all the flesh with a spoon. Either mash potato or pass through a food mill into a pot.
Place pot over low - medium heat and begin adding butter one cube at a time. Once all butter (it may slightly split but that's ok) is incorporated add just enough cream to bring it together and make it velvety smooth. Season with salt and white pepper.
Finish beef olives with chopped parsley and serve over mash with plenty of sauce.