Things to chuck in:
spices (anything you fancy from cinnamon to cardamom to garam marsala or moroccan mix)
fresh herbs (whatever you have on hand)
sauteed mushrooms & toasted pinenuts
roasted pumpkin chunks and roasted capsicum
semi-dried tomatoes (diced) and cubed feta
handful of currants and a bit of curry powder

As you can see, this is an endlessly variable substance! I always start with stock and spices and then just chuck whatever in. Mmmmm.