You carve a roast. This has been the way it has been said since at least Chaucer's time. So yeah, you carve the chicken, turkey, beef, lamb, or venison roast . But you might cut the roast into pieces before it's cooked. Carving is sort of that special moment when the roast is just ready to eat. Now for Americans, casseroles are sort of the antithesis of a roast, so you would cut or slice it, or dish it out. They usually involve moisture and some form of starch, so the meat is intended to be soft.