For the lobster preparation, place live lobster in freezer for 1 hour, where it will ‘go to sleep’ (the cold stuns it).
Bring to the boil a pot of water that is large enough to fit 2 lobsters. Cook the lobsters for 10 minutes
Meanwhile, start making the Russian salad by peeling the potatoes and putting them in a pot of cold water. Bring to the boil, reduce the heat and cook until the potatoes are soft but not falling apart. Add the carrot and peas about 5 minutes before the potatoes are ready. Drain and allow to cool completely.
Drain lobster, place under cold running water until the lobster has cooled completely. Twist the head and tail of the lobster in opposite directions. Remove the tail fins and gently break the shell, trying not to break off or tear any of the flesh.
Slice the lobster tail into 5mm medallions. Separate the top from the bottom of the body, remove the legs and break open the joints where the legs meet the body. Pick the meat out of the joints and then break open the legs and extract the meat. Using a mallet, break open the antennae to get the meat from them. Set all the meat aside.
Put the beetroot in a small pot with wine vinegar and sugar and cook until tender.
To make the mayonnaise, whisk the egg yolks, mustard and vinegar in a large bowl. Whisking constantly, slowly drizzle in the oil, at first drop by drop. The mixture will thicken and have a dull appearance. Season with salt and pepper to taste. You should have a thick mixture in which a spoon will stand upright.
Gently crack 1 quail egg into a cup, taking care not to break the yolk. Half fill a small frying pan with water, add a splash of white vinegar and bring to the boil. Reduce heat until barely simmering, using a slotted spoon, swirl the water around to make a whirlpool. Tip in egg and cook for 2 minutes. Remove and drain on paper towel. Keep warm while you repeat with other eggs.
To finish making the Russian salad, cut the potatoes into small dice about the same size as the carrot. Mix with carrot, peas, mayonnaise and horseradish, season to taste. You may need to add a little more mayonnaise if the mixture is too dry.
To serve, spoon some Russian salad into the centre of each plate. On top of this put some lobster meat from the legs. Arrange a few slices of tail meat on top, a quail egg and 2 slices of bottarga. Drizzle beetroot reduction around plate, scatter over a few watercress sprigs and drizzle with a little oil.