Add the onion, garlic, rosemary & thyme to a heavy bottomed pan on a high heat, cook down till the onions are just starting to colour then add the brandy and porto, being careful as this will cause a flame. Reduce mix till nice and sticky.
Add the butter to a flat bottomed tray and place in an oven at 180 degrees.
Once the butter is melted, add the livers and onion reduction to the tray with the butter and place back in the oven at 180 degrees for 15 mins.
Once cooked, blend mix either with a hand held blender or a food processor until as smooth as possible.
Once smooth, add mix to a container of your choice and place in the fridge till cooled and ready to serve.
Prep the livers ahead of time and soak them in milk, the fats in the milk help to break down the toxins in the livers and remove the bitter taste usually associated with pâté.
To seal the top of the pâté from the air add some clarified butter to the top and let set.