In a heavy 10- to 12- inch skillet, melt 2 Tblsp. butter with the oil over high heat. When the foam subsides, drop in half the veal and, tossing the strips about constantly with a fork, fry for about 2 minutes.
When the veal is delicately colored, transfer it to a large sieve set over a bowl. Melt 2 more Tblsp. butter in the pan, then drop in remaining veal and cook as before. Add the veal and its juices to the veal in the sieve.
Add the remaining butter to the pan and melt it over moderate heat. Then stir in the shallots and cook for about 2 minutes before pouring in the wine.
Raise the heat to high and stir until the liquid comes to a boil. Immediately add the cream and all the drained veal juices.
Stirring constantly, boil briskly for 8 to 10 minutes, or until the sauce has reduced to about half its original volume and thickened lightly. Taste for seasoning.
Return the veal to the skillet and turn it about until it is thoroughly coated with the sauce. Simmer over low heat for 2 or 3 minutes until the veal is heated through. Serve at once, accompanied, if you like, by Rosti.