Wash the veal tongue under cold running water and pat dry. Peel the onion, make a couple of incisions all the way round, insert the laurel leaf and fix in place with the cloves. Crush the peppercorns. Bring a large pan of water to the boil, then add the wine, pepper, onion and tongue. Cover with the lid and bake for approximately 2.5 hours at 70°C (158°F) until the meat is soft. Run the tongue briefly under cold water and remove the membrane. Pass the stock through a fine sieve and then add the tongue.
For the apple sauce: slice the vanilla pod open lengthways and scrape out the seeds. Add the seeds to the apple juice, sugar and lemon juice and bring to the boil. Peel the apple, cut it into quarters and remove the core, then chop the apple into small pieces. Add the chopped apple to the boiling liquid, cover the pan and leave to simmer gently for 20 minutes. Then finely mash or puree the mixture. It can be served hot or cold.
For the potato pancakes: peel the shallots and potatoes and grate them medium-finely. Mix the egg and the potato starch together to form a mixture and season with pepper. Heat the oil in a pan. Spoon small portions of the potato mixture into the hot oil and fry them until they are golden brown on both sides. Remove the excess grease on paper towels after cooking.
Serve the apple sauce separately in small dishes. Remove the tongue from the cooking liquid and cut it diagonally into slices of approximately 1 cm (0.39 inch) in thickness. Arrange the slices onto warm plates alongside the mini potato pancakes and serve immediately.