If this is not frugal I don't know. And delicious to boot. I had this for breakfast which may seem strange, but I always start the day with (leftover) soup.
Bread Pudding Soup:
leftover bread pudding (it had no sugar, honey or milk in, only figs, raisins, cinnamon)
leftover cooked pumpkin,
beetroot cooking water,
3 spoonfuls of yoghurt
soy - salt - garlic.
It has a lovely colour, and you can add some parsley for the contrast.
A nice surprise!