My favourite (and absolutely foolproof) recipe is for steak and ale pie or casserole.
Toss cubed beef in flour mixed with salt, pepper and mustard powder, and fry in batches, putting the meat in the slow cooker when sealed. Then fry baby onions and thickly chunked carrots and add them to the cooker. Deglaze the pan with a bottle of Guinness or strong-flavoured ale and pour the scrapings and the rest of the bottle onto the meat and veg. Cook for 3 hours or so and chill. Next morning (or later in the day, depending on timing) remove any fat that has hardened or scoop out oil, and taste. Add in a red wine stock pot and seasoning as required (herbs can be added at this point too) and turn on the cooker on low. Cook for a further few hours until the meat is tender and the veg soft. Add a pastry top if liked, and serve with roast potatoes and more vegetables on the side.
I’ve made this countless times and it has never gone wrong. The trick is in tasting half way through and using your judgement to add whatever is necessary. I find that adding the wine stockpot half way through is good, too. I have been known to add a gravy pot at the end if the liquid feels ‘lacking’.