Heat the clarified butter in a large pot over medium-high heat. Working in batches, brown the veal cubes on all sides, about 2-3 minutes per batch. Remove the browned meat and set aside.
In the same pot, add the diced onion, carrot, leek, and celeriac. Cook over medium heat for 5 minutes, stirring occasionally, until softened.
Return the veal to the pot. Add the veal stock and wine, then add the bay leaf and cloves.
Cover the pot and simmer over low heat for 45-60 minutes, until the veal is tender. Remove the bay leaf and cloves.
Stir in the cream and simmer for another 5 minutes to reduce slightly. If you want a thicker sauce, mix flour and butter together to make a paste and stir it into the sauce.
In a small bowl, whisk together the egg yolks. Slowly whisk the egg yolks into the hot sauce while stirring constantly to prevent curdling.
Season with salt, pepper, and a pinch of sugar. The sauce should have a sour taste.
Serve with broad ribbon noodles tossed in butter or homemade spaetzle.