On a work surface, lightly pound the pork slices to a 1/4-inch thickness. Rub with the sage and season with salt and pepper. Dredge the pork in the flour, shaking off any excess.
In a large skillet, melt 1 tablespoon of the butter in the olive oil. Add the pork and cook over moderately high heat, turning once, until lightly browned, about 5 minutes. Transfer to a platter and keep warm.
Add the shallots to the skillet and cook, stirring often, until golden, about 2 minutes. Gradually add the Madeira and bring to a boil, stirring; boil until reduced to 3/4 cup. Return the pork to the skillet and simmer, turning twice, until cooked and the sauce is slightly thickened, about 3 minutes. Arrange the pork on plates. Swirl the remaining 1 tablespoon of butter into the sauce and season with salt and pepper. Spoon the sauce over the pork and serve.
Pork is such a light meat that it can pair nicely with either a red or a white wine. Here the strong flavor of Madeira tunes the dish to a light but intense red, such as a silky, fruity Pinot Noir.