Beef heart tends to constrict and solidify when cooked, rather than turn into loose stringy bits like other meats.
They make good kebabs according to a recipe I found...
Marinated overnight in ground cumin, garlic, chilli and oregano mixed with olive oil and red wine vinegar, the thinly sliced heart is then concertinaed onto wooden skewers before being grilled over hot coals.
Cooked quickly like this means the meat has little opportunity to constrict and toughen up. The light charring of the barbecued meat adds a warm, deep savoury note and the marinade, pepped up with the sharpness of vinegar, really lifts the dish.
After 5-6 minutes over hot charcoal, the meat was picked off the skewer onto a hot flatbread and served with rocket, a few spoonfuls of mayonnaise and the leftover marinade cooked down with some tomato puree.
And here is a recipe for spiced ox heart...
serves 6
1 kg (2 lb) ox heart, hard parts and sinews removed, cut into cubes
1 tbsp cooking oil
3 tbsp (1 1/2 oz) 40 g butter
2 large onions, chopped
1 clove garlic, crushed
2 tsp salt
freshly ground black pepper to taste
375 ml (12 fl oz) meat stock
2 bay leaves or lemon leaves
3 whole cloves
1/2 tsp each Mixed Spice (All Spice / Pumpkin pie spice) and grated nutmeg
2 tbsp lemon juice
4 tbsp plain flour
method
1. Brown meat in heated cooking oil and butter in a heavy-based saucepan.
2. Add onion and garlic and saute until onion is translucent. Season with salt and pepper.
3. Heat meat stock and add to meat together with remaining ingredients except lemon juice and flour.
4. Cover with lid, reduce heat and simmer for 2 1/2 to 3 hours or until meat is tender.
5. Remove bay leaves or lemon leaves and stir in lemon juice.
6. Thicken sauce with a flour and water paste.