Chocolate jelly

1.For bitter chocolate jelly, stir sugar, coffee and 1 litre water in a large saucepan over medium-high heat until sugar dissolves, then bring to the boil. Remove from heat, add chocolate, stand for 5 minutes, then whisk until smooth. Squeeze excess water from gelatine, add to chocolate mixture, stir until combined, then set aside to cool slightly, whisking occasionally. Pour into a 2.25-litre fluted mould and refrigerate until set (4-5 hours).

2.For white chocolate jelly, bring milk to a simmer in a saucepan over medium-high heat, then remove from heat, add chocolate, stand for 5 minutes, then whisk until smooth. Squeeze excess water from gelatine and stir into add to chocolate mixture. Gradually whisk in crème fraîche, cool briefly, then pour onto bitter chocolate jelly in mould and refrigerate until set (3-4 hours).

3.Dip mould in a saucepan of hot water, pull jelly gently away from sides to break the vacuum, place a serving plate on top, invert mould and plate, then remove mould. Serve with biscuits and crème fraîche. Jelly can be made 2 days ahead.