From 1911:
Take a beef heart, clean it carefully, fill with a dressing made as for chicken or turkey. I use an equal amount of mashed potatoes and breadcrumbs, seasoned with sage, summer savory, pepper and salt, and moistened with beef drippings or butter, and add 1 or 2 chopped onions. Fasten together with skewers or twine, steam 4 hours, and bake 1 ½ hours, basting well. Make a thickened gravy of the drippings.