Hearts from chickens, lambs, cows and pigs are all good for cooking and are fairly easy to find. Working as hard as they do during the life of the animal, hearts are very lean, aside from a layer of fat on the outside.
Fairly easy to find compared to some other offal, hearts are inexpensive and easy to prepare. As with all offal, fresh is best, so build up a relationship with a good butcher or small producer for the best-quality heart.
As such, they should either be cooked quickly over a high heat, or slowly with liquid or a moist stuffing. If you are cooking heart quickly, try marinating overnight to help tenderise, then grill, barbecue or fry over a high heat for a matter of minutes. To slow cook, try stuffing and braising the heart, or cut it into slices and stew. A slice or two of pan-fried ox heart makes a quick and satisfying sandwich (a slathering of horseradish suits it well).