Bring the bouillon to the boil, plunge the lobster in and poach for 4-5 minutes, then allow to go cold in the liquor. When cold, remove the meat from the shells. Cut each claw meat in half lengthwise and the tail meat into 12 slices across.
Remove any sinew and bones from the chicken breasts and cut the meat into slivers about 5 mm/14 inch thick. Prepare the vegetables. Peel the carrots and the turnips to retain their natural shapes, top and tail the mangetout and beans. Break the calabrese into small florets. Blanch them all in boiling salted water for a few seconds and then refresh in ice cold water.
Heat the oil in a frying pan and, when hot, add half the butter. Season the chicken and quickly fry it in the fat without colouring until sealed. Tip off the fat, add the brandy and the sherry to the pan and reduce until the liquid has almost gone. Pour in the lobster sauce, bring to the boil and reduce a little, then add the cream and return to the boil. Allow the sauce to reduce slightly until it just starts to thicken, then add the chicken and simmer until the chicken is cooked, about 2 minutes.