Wash, dry and season the livers. Put into a small tin and add the butter and onion. Cover with greased greaseproof paper.
Place trivet in the pressure cooker, add 1/2pt water, then stand the tin on the trivet.
Fix the cover, bring up to H/15 lb. pressure, then cook for 3 mins. If liver thinly sliced.
Reduce pressure under cold water, lift out the livers and pound with the onion and butter until smooth. Cool, then blend with the cream and brandy or sherry.
Dice the tongue and stir into the pâté.
Cover the dish with foil or melted butter. Store in the fridge for at least 24 hours before serving.