Saute medallions quickly in the 1/4 cup butter until they are lightly browned on both sides.
In a saucepan, cook mushroom caps in the 2 tablespoons butter and season them lightly with salt and pepper.
Arrange the medallions in a warm serving dish; put the mushroom caps on top of them.
To the pan in which the veal was sauteed, add the wine and stir over low heat 1 minute.
Add the 1 tablespoon butter, swirl the pan over heat until the butter is melted, and pour the sauce over the medallions.
Serve at once.