Clean and truss 2 plump pheasants and sauté them in half the butter in a heavy-bottomed frying pan until they are nicely browned on all sides. Remove and keep warm.
Peel, core and slice apples, and sauté them in remaining butter until they are golden. Place apples in the bottom of an earthenware casserole; arrange pheasants on top and baste with the pan juices thinned down with Calvados; cook the birds in a moderate oven (375°-M4) for about 30 minutes.
Add cream and the juice of ½ lemon, and season to taste with salt and freshly ground black pepper. Return the casserole, covered, to the oven and cook until the birds are tender and the sauce is creamy and thick.