In a slow cooker I just bung them on the top about 30 mins before I dish up .If the cooker has been on low as for a stew ,casserole etc I whack it onto high ten minutes before I put the dumplings in . Recipe as per Woofy . I usually do two heaped Tbsps SR flour and one heaped Tbsp of suet ,salt and pepper .
You can add anything ,cheese ,herbs etc. Just remember the weight must tally .Two to one .
This divides into about eight dumplings .
Or you can steam them separately in a colander over a saucepan of boilng water and serve them up with whatever you are sozzling in the slow cooker .