1. Cut the potatoes into large even sized pieces, place in a medium sized pan and leave under a cold running tap for 5 minutes to remove the excess starch.
2. Place the pan on a heat and season the water with salt. Bring to a boil, and then gently simmer the potatoes for 20 minutes or until the potatoes break open easily when poked with a knife.
3. Drain the potatoes and leave to dry out for 10 minutes.
4. Put the potatoes through a potato ricer, then back into the pan, add the milk and beat with a wooden spoon, until the mixture comes together.
5. Place the pan with the potato mixture on a gentle heat, and then slowly add the butter, whilst beating with the wooden spoon. When all the butter has been added, season with salt and pepper, cover and leave in a warm place.
6. Heat the oil in a non-stick medium sized frying pan over a medium heat. Add the garlic and cook until slightly golden, then remove from the oil and set aside, add the butter to the frying pan and turn up the heat slightly, when the butter starts to brown add the sturgeon livers and season with salt and pepper. Cook for 3 minutes on each side or until just cooked. Remove the livers from the pan and leave to rest in a warm place.
7. In another non-stick pan heat the oil and butter, when the butter starts to brown, add the broccoli and cook for 2 minutes, then remove from the pan.
8. Give the pomme puree one last beat then divide between 4 warm bowls, top with the sturgeon livers, broccoli and toasted garlic.
9. Using a truffle slicer, slice the truffle over the bowls, then drizzle with the truffle oil and serve.