Of course pomegranate molasses isn't the same thing as molasses at all, but its tartness works really well in this marriage of sweet and sour.
It is not for me to use such terms as 'genius' to describe the inclusion of jerk barbecue sauce in this dish - that is what the comments section is for - but it combines with the triple smoked pork belly to give the beans a wonderfully gutsy bonfire night flavour.
You could, of course, use smoked bacon for this or even splash out on some actual pancetta (and for a really cheap dish, Asda sell what they term 'Smoked Bacon Cooking Pieces' for £1.48/kg), but none, I'll wager, will impart quite so much depth and complexity .
recipe
200g dried haricot beans
a splash of groundnut oil
600g-700g triple-smoked pork belly
1 large or 2 medium onions, roughly chopped
3 garlic cloves, crushed
200g tinned tomatoes (half a tin, including juice), mashed up
2 tbsps muscavado sugar
2 tbsps jerk barbecue sauce
1 tbsp pomegranate molasses
1 tbsp dijon mustard
1 tbsp white wine vinegar
200ml water, plus more water to cover in casserole
black pepper
Soak the beans in plenty of water overnight.
Drain the beans. Remove the skin from the gammon, lay at the bottom of a casserole dish and tip the beans on top. Cut the gammon into chunks, place in a large frying pan and heat slowly to allow any moisture to seep out. Tip the gammon chunks into a sieve to drain. Wipe the frying pan, increase the heat to fairly high, add a splash of oil and fry the gammon until nicely browned.
Now throw the tomatoes and juice into the frying pan. Stir, scraping up all the crusty bits from the base of the pan. Add the sugar, barbecue sauce, molasses, mustard, vinegar and 200ml of water and stir. Pour over the pork and onions in the casserole. Top up with more water until everything is just covered.
Put the casserole into a 160C/140c fan oven for approx 4 ½ hours. Check liquid level after 2 hours and then every hour after that, topping up with more water as necessary; after 3 hours, remove the gammon skin and discard.
At the end of the 4 ½ hours, the beans should be squidgily soft and the sauce should be nice and thick. Season with black pepper - it won't need any salt (and for this reason do not be tempted to replace the water with stock made from a stock cube).
Serve with crusty bread and a plain, green salad.

