Using a heavy knife, cut through the heads of the lobsters in one swift movement. Pull away their tails and claws, and remove and discard the gritty sac from just behind the eyes. Roughly chop up the bodies and any coral and set to one side. Cut each tail into 4 pieces through the joints of the shell and crack the claws with the back of the knife.
Heat the oil in a roasting tray or ovenproof pan. When hot, add the mirepoix of vegetables and quickly fry for about 30 seconds. Add all the pieces of lobster, including the bodies, and continue frying and turning the lobster in the oil for a further minute, then transfer to the oven and cook for 10 minutes, turning occasionally. Remove from the oven and take out the tails and claws and allow them to cool; leave the chopped bodies in the pan. Add the red wine and the garlic to the pan and reduce by two-thirds. Then add the fish stock and reduce again by two-thirds.
When cold enough to handle, remove the lobster meat from the claws and tails, cover and keep warm. Roughly chop the shells and add these to the reduction. When the fish stock has reduced far enough, add the veal stock and continue boiling until it starts to thicken.