For cooking Ox Heart it's best to rinse in cold running water
for a hour or so, next place in a deep stock pan, cover with
essential cuisine beef stock, a large onion, 2 large carrots, a few
sticks of celery all roughly chopped, some thyme, bay leaf, few
white peppercorns, 6 whole garlic cloves and a half bottle of red
wine.
Bring to the boil, skim off any white proteins on the surface
then reduce heat to a simmer and cook for 3 hours 30 minutes until
tender when pierced with a skewer at the thickest point.
Leave the heart to cool in the broth for an hour or so then
pass of the juices and reduce to a rich syrupy sauce adding a
spoonful of corn flour mixed with cold water and whisked into the
sauce to thicken slightly.