How to fix a sauce with overheated yogurt that has separated?
Did it and rescued it - important extended family meal and I took a curds and whey disaster to a great sauce! I cooked up chicken with its yoghurt base marinade, the yoghurt split. It tastes fine it's just the proteins have changed at high heat and clumped to form curds.

To solve it I:


took a small amount of water (2 tablespoons or so) in a jug and mixed in a couple of teaspoons of cornstarch. I then added this to the sauce. Don't add cornstarch directly or it will just lump.
OPTIONAL: take other sauce ingredients that are meant to be whole (tomatoes in my case) and add 1/2 to sauce
blend to a smooth sauce using stick mixer (careful of hot sauce splashes)
Reduce sauce, if necessary, to thicken sauce on a medium heat stirring frequently
Return chicken to sauce and add the rest of the ingredients.


Serve and eat, and not to self "next time you cook with yoghurt do it slowly on a low heat - DO NOT BOIL"