Ox heart stew.

 I saw this in Morrison's, back in late Autumn, and since I'd heard it was good, decided to give it a go.

 I poked around in my books and online, and decided to go for a plain, traditional stew recipe.
The heart had some lumps of just plain fat, I chucked those, and cut off any visible pieces, I know fat is OK when it melts down, but I had no idea what heart fat would do, and didn't want to chance it.

First off, sliced two large onions, lobbed in slow cooker with slug of olive oil. Left for three hours till softened and caramelising.
Heated Olive oil in pan, added heart in batches to brown, and get quite crusty in places, removed to a plate when done.
Added flour to thicken juices, and poured in beef stock to deglaze (wine would be good here, I had none), added in squeeze of tomato purée, few splashes of Worcester sauce and a big pinch of mustard powder, plus salt and lots of freshly ground pepper.
Added heart back to the pan, stirred around to combine, then chucked all into slow cooker and left on low overnight.
Got up in morning, sauce seemed quite thin, so took the lid off and left to reduce down all day.
When it came to 45 minutes or so before serving, I transferred it to a pyrex, made dumplings and put them on the top, then cooked in the oven.
I served it with candied carrots (carrots cooked with butter and sugar).
Utterly delicious, not offally at all, and has a great texture, with chew but not chewy or stringy.
I will be buying it again.