I use ours for stews a lot.
Lamb stew (this is me writing it down but it's all sort of in my head and I wing it a lot).
Lamb shoulder or neck, cut into chunks (quantities really up to you - I tend to do about 600-800 g and would consider that enough for 2 meals for the four of us. If you like it very meaty, do 600g for one meal and lower veg etc). Please do not buy "stewing lamb in chunks" from the supermarket. It is never fatty enough.
Dredge the lamb in seasoned flour and brown in a saucepan. Tip into slow cooker.
Sweat/saute chopped onion (and any other obvious ingredients you have lying around such as celery, leek etc). Do not add garlic because, in my experience (although I think it has something to do with the type of slow cooker you have) the garlic will taste funny when it is slow cooked. Tip into slow cooker.
Peal and chop (into big chunks) carrots or other preferred veg of this sort. Butternut works well but doesn't freeze well if you're planning to save leftovers (goes mushy - tastes fine, but doesn't look as good). I hate turnips/parsnips but those would, of course, work.
in the pan throw in a generous amount of red wine add a tin of chopped tomatoes or passata, a large cinnamon stick, two star anise, a drizzle of honey, a bay leaf and, if you like, a clove or two. Bring to the boil. Add to slow cooker.
Add a stock cube (I use the gel ones) and then top with boiling water from the kettle enough to just about cover everything. (A few things poking up is fine). Stir enthusiastically to dissolve stock cube. Add salt and pepper. Cover and cook for approximately 4 hours on low or 8 hours on high. On mine, I can eat it at that point or leave it for up to about five hours on high or 10 on low.
By itself, that will work nicely. I usually open it up about 30 minutes before and add a tin of cannellini beans or a tin of chickpeas to up the nutrition and to make it go further. Another variation is to add about half a cup of puy lentils at the beginning (may require a bit more liquid). My mother always adds peas to her lamb stews - usually by microwaving them for 3 minutes then stirring in immediately before eating (again, peas don't work as well as leftovers or when frozen so this is best if you're going to eat the entire thing in one go).
For beef, I do the same flour/fry/onion thing but add LOADS of ginger with the onion mix. I might add a little passata for thickness but only about half a small box. Little bit of white wine, a bay leaf and maybe a clove. Usually add lentils rather than beans/chickpeas.