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• Livers: peel the livers and cut them into bite-sized pieces that are as uniform as possible. Rinse them in cold water, drain them and dry them by gently dabbing them with kitchen paper. Add salt just before cooking. Preheat a pan with a little olive oil and add the livers. Cook them over high heat for a short time. Toss them every 15 seconds and check that the outsides are evenly coloured. After cooking for 1 minute, mix in the brandy and reduce it by cooking for another minute. Take the pan off of the stove and set aside.
• Onions: clean them and cut out discs with a maximum thickness of 1 centimetre. Be careful to keep the discs intact. Place the onion discs in a non-stick pan with a spatula and sprinkle a mix of salt and sugar on both sides to caramelise the onion. Remove from the pan and set aside three discs for each plate.
• Gruyère: grate and set aside
• Chocolate: grate on baking paper and set aside in a cold place

Plating: 
Arrange three discs of the lightly caramelised onion on the plate used to serve the cooked livers. Sprinkle a little chocolate on the top and then some grated Gruyère.