Step 1
Use a sharp knife to butterfly the pork if you haven’t asked your butcher to do so. Season generously with salt and black pepper. Let rest for at least 45 minutes.
Step 2
Meanwhile, prepare the filling. In a heated large saucepan, heat the olive oil and butter over medium-low heat. Add the sage and garlic until sage is crisp and garlic almost brown. Spoon out with a slotted spoon and set aside. In the same pan, fry the mushrooms and lemon in the butter and oil (add a bit more if necessary) until golden brown. Season salt and black pepper. Set aside and allow to cool.
Step 3
Preheat oven to 160°C (325°F). Arrange the slices of pancetta in a layer on top of the meat, followed by the garlic, crispy sage leaves, and mushrooms. Roll up the meat tightly and secure with butcher’s twine (or cable ties) at 2 cm intervals to form a tight roll.
Step 4
In a cast iron pan, sear the pork roll all over in 30 ml oil until very brown. Put the roll in an oven-proof casserole and drizzle the lemon juice all over. Add the onions, bay leaves, apples, and beer. Cover with lid or foil and roast in the oven for about 2 hours until meat is soft and tender. Remove the meat from the casserole dish and let rest for 10 minutes before carving.
Step 5
After about 1 ½ hour, scoop out 250 ml of meat juices from the roasting pan/casserole for the sauce. In a small saucepan, heat the butter. Stir in the flour and cook for another 2 minutes. Whisk in the stock, milk, and apple cider. Add the chopped sage leaves. Cook over low heat until thick-ish, stirring occasionally, about 5 to 8 minutes. Stir in 45 ml butter and whisk until well incorporated. Serve with meat.
