I remember having heart as a child, and enjoying it, so when I came across it on the Wild Beef stall, I had to try it. (It is cheap, too: £4.50 for a heart which will feed two people easily, or four people if there are enough vegetables).
I was told that because it was good quality muscle meat one could just cut the heart into strips and fry it quickly. I didn’t try this, because it wasn’t how I remembered it and I wasn’t sure how well it would work. So here is what I did instead. I didn’t look up any recipes – I just guessed. So I may have made many mistakes, but the result was still very edible.
To prepare the heart: Cut it open and remove anything that is obviously not meaty. For instance, there are strong sinews holding the whole thing in shape, and there may also be tough linings to some of the blood vessels and heart valves. How much you remove depends on how sharp your knife is, how sharp your eyes are, and how confident you are. I removed quite a lot because I wasn’t very confident. I’ll take more care next time.
I also removed the layer of fat on the outside of the heart, but on reflection I think I needn’t have done that because the fat would have melted away during cooking. It was only a thin layer anyway.
Chop the meat into small pieces. I would guess that mine were a bit smaller than half-inch or one-centimetre cubes.
Heat the oven to 170°C.
Heat a small amount of oil in a frying pan. Put the meat into it and fry it until the outside of most of the cubes is brown. You are not trying to cook the meat, only seal it. A thick gravy will come out of the meat, which means that your frying will turn into boiling eventually. Don’t worry about that: it probably means that you have done enough frying and you can stop. Salt the meat a little when you are frying it, but not much, because not much salt is needed.
Put the meat into a casserole together with a 400g tin of chopped tomatoes (mine were “chopped tomatoes with garlic and olive oil”). I put the tomatoes in the casserole and heated it on the stove until the tomatoes were starting to boil, then added the meat. But equally you could add the tomatoes to the frying pan and turn up the heat until everything is at boiling point, and then pour it all into the casserole together.
Put the lid onto the casserole and put it into the oven. Set the timer for 70 minutes, and go to bed. In the morning, take it out and put it in the fridge. When you want to eat it, warm it up.
This means that in practice it will have cooked for a bit more than 70 minutes, because the oven will have taken time to cool down after it switched itself off. So for a daytime version of this recipe, you might say “80 minutes and take it out”, or “70 minutes and then have a look at it”.