We have been using a Remoska instead of using the oven (it can virtually cook anything), it only uses 500w, over the year it has saved us a fortune. We have also purchased some very low power fan to place near the radiator to circulate the heating in the rooms.
I/we tend to use a slow cooker for most things that would otherwise need to becooked in the oven or the zapper if cooking a bit of veg for previously cooked meat or for beans on tast.