How to Make It
In a large deep skillet, melt the butter in the olive oil. Season the hen pieces with salt and pepper and add half of them to the skillet. Cook over moderately high heat, turning, until browned all over, about 8 minutes; transfer to a plate. Repeat with the remaining hen pieces.
Add the shallots to the skillet and cook over moderate heat until softened, about 3 minutes. Add the cider, stock, Calvados and vinegar and simmer over moderately high heat, scraping up any browned bits from the bottom of the pan, until slightly reduced, about 5 minutes. Add the apples and heavy cream and bring to a simmer. Return the hens to the skillet and simmer over moderately low heat until an instant-read thermometer inserted into the thickest piece registers 160°, about 10 minutes. Transfer the hens to a platter. Add the currants to the skillet and season the sauce with salt and pepper. Spoon the sauce over the hens and serve.