Black eyed bean shepherd's pie was a recent success.
Chuck the beans (dried) into the slow cooker & cook over night - they need a couple of inches water/stock on top of them. They should be mostly tender but with a bit of 'bite' after this.
Next day, saute a chopped onion, couple of peppers, few cloves of garlic, & a sliced chilli & throw them into the slow cooker too.
Add a jar of pasta sauce or homemade equivalent, or even just tinned tomatoes. Then a good shake of molasses, barbecue sauce, & balsamic vinegar - anything sticky & sweet basically!
Cook for another couple of hours until beans are tender & sticky.
Transfer to a baking tray, top with mash (I used sweet potatoes)& shove in oven for half an hour until the beans are bubbling & the mash has crisped up.
Sounds like a faff, but genuinely the slow cooker does the work other than chopping a few veg. Plus ridiculously cheap, full of protein & vegan.
I had more beans than I needed for the pie so put them in the fridge. Carnivorous ds who is generally rude about vegetarian dinners scoffed them on toast for breakfast!