Cook bacon in a very large frying pan until crispy and set aside, leaving the bacon fat in the pan.
Add the butter to the bacon fat, as well as the diced onions and fry until the onions are beginning to caramelise.
Add in the chicken livers and brandy and saute for around 10 minutes, continually turning the livers, until the livers are just cooked through. The residue heat will continue to cook any underdone parts.
Sprinkle the nutmeg and sage leaves over the top and gently mix in.
Ladle the mixture into a food processor, crumble in the bacon and blend into a paste.
Taste the blended mixture and add salt and pepper according to your preference.
Pour the mixture into your desired jar, dish or container and leave to cool in the fridge for at least 40 minutes.
When your pate is cool, it's ready to eat.