Current favourite is a gammon joint, throw in a halved onion, maybe a carrot or celery stick, a few peppercorns, bay leaf, star anise (if you like), cover with water. Cook for a few hours.
I like to then score the fat, glaze with honey/mustard and bake for 25-30 minutes but it's not necessary.
If the cooking liquid isn't too salty, I use it as a base for curried lentil soup.
Pulled pork also works well.
After numerous trials, for reliable and easy everyday chilli/spaghetti bol etc, I tend to use a Schwartz -type packet mix with mince, frozen onion, tin of tomatoes, tomato purée, tin of kidney beans, maybe peppers, dash of Worcestershire sauce.