Well spotted! no tomato in this one simply because I was trying something new.
There are also no peppers, coriander stalks, carrot, cabbage, swede, secrets or any other ingredients that have been suggested in the past.
Yes you can add what you like but the results will be different.
The slow cook idea may not be anything new- but for me it is- I think it made a massive difference and like I tried to suggest, the whole process was effortless. Simply banged it all together with very little chopping and stiring. The times I've almost finished cooking a base only to burn it through a moments neglect.
The recipe would probably make about 8 good size curries but as you can appreciate it depends on what your making.