a sour cream substitute
 

I had no sour cream in the house and a baked potato was about to be
served. I rooted around in the fridge and located a bit of cottage
cheese ( I really need to get to the market), added a T. or two of
yogurt whey, some dulse flakes and mashed it with the potato masher.
It wasn't half bad, if a bit cheesey.

HTH