1. In a deep frying pan, melt a knob of butter and soften the onion and garlic. Add the thyme and chicken livers and cook gently until the livers have stiffened and turned brownish.
2. Season then pour over some brandy or sherry. Cook until the alcohol evaporates then transfer to a food processor, removing the thyme twig but retaining its leaves. Whizz until smooth. Add some butter if you'd prefer a richer taste.
3. Melt some more butter and add more thyme leaves. Spoon the paté into a bowl, smooth the surface and pour on the melted thyme butter. This would now benefit from a day's rest to allow the flavours to develop.
4. Spread a little butter and paté on to each piece of bread and top with a long slice of cornichon or gherkin.