"Share The Meat" recipes. Braised stuffed heart. Brown the hearts on all sides in fat, then place in a covered baking dish or casserole. Add a half of cup of water, cover closely and cook until tender in a very moderate oven (about 300 degrees Fahrenheit). Calf hearts require about one and a half hours, beef hearts will require much longer--four to five hours to cook till tender. Sourced from the Library of Congress.