Remove the largest outer leaves of the cabbage and reserve to wrap the cabbage rolls
Thinly slice the small inner leaves and set aside
In a large frying pan, heat a glug of oil over medium heat and brown the guanicale with a big pinch of salt and black pepper
When guanciale is cooked through and browned, remove from the pan and add the onion, garlic, and sage then reduce to low heat to sweat (if omitting the pork simply sweat the aromatics in olive oil)
When the onions are soft add the apples and reserved cabbage cook until just starting to soften
Remove from the heat and in a large bowl combine the onion apple mixture with the reserved guanciale, the cooked wild rice, and chopped walnuts and allow to cool
When cool roll approximately 3/4 cup of the filling in the reserved cabbage leaves (more if the leaves are larger, less if smaller) and transfer to a baking dish
To heat, drizzle the cabbage rolls with olive oil and a sprinkle of salt and black pepper and then bake at 375F until warmed through and the outside is slightly crispy