Heat the butter in a frying pan. Fry the bacon for 2-3 minutes over a medium/low heat until just cooked but not too brown.
Add the onion and garlic and continue to fry for 3-4 minutes, until the onion is just soft. Add the lamb's liver and cook for 4-5 minutes, add the tomato purée and brandy, stir well and continue to cook for another 2 minutes over a medium/high heat to make sure the alcohol is burnt off.
Leave the liver to go cool, add the crème fraîche and transfer the mixture to a blender. Blitz until smooth and season to taste.
Spoon the mixture into ramekins, or a small serving dish. Smooth the pâté in the dish and pour over the melted butter. Garnish with the bay leave and peppercorns. Allow to chill in the fridge for at least 2 hours before serving.
To make an extra smooth pâté push through a sieve before filling your serving dishes.
Delicious served with lightly toasted brioche!