Ingredients (serves about 8)

For the white gloop

For the coffee jelly

Method

  1. Soak the gelatine sheets in cold water for a few minutes until they become spongy.
  2. Disolve the coffee in the boiling water. You could obviously just use espresso here, but I've read that Michel Roux uses instant coffee in his tiramisu and I see no reason to argue with him. Don't add any sugar though: you want to jelly to be almost bitter.
  3. Remove the gelatine from the water, and squeeze to remove any excess water. Add them to the coffee while it's still hot, then stir to disolve.
  4. Pour the liquid onto a non-stick baking tray (with raised edges) and leave somewhere cool, e.g. a fridge, to set. You should find that the sheet of jelly is about 0.5mm thick. This thin sheet has a large surface-area to volume ratio, which gives a strong hit of coffee in the mouth.
  5. Whisk the egg yolks, vanilla and sugar until they reach a mousse-like consistency.
  6. Thin the mascarpone by mixing the cream with it, then genty fold in the egg and sugar mixture.
  7. Cut the sheet of jelly into small squares (it's not necessary to take much care over this), then gently mix them into the mascarpone mixture. You might not need all the jelly, so check the balance of flavours as you proceed.
  8. Put the mixture into a serving dish and chill for at least a few hours.