Lack of Hygeine

OP,
your MIL has very disgusting habits in kitchen...puke puke, the curd one was the worst. Mine has some similar ones and when I am eating my meals at at MIL place, I feel like throwing up before every meal...works wonders for my weight- 10 days and 10 pound is easy.
I have nothing so far, just bear. I cannot because mine ILs are real bad people.
But looks like you are only few years into your marriage, better to do somthing about it now.
One solution, not sure if it will work for you: have a small deity in kitchen or near, start offering all food, prepared drinks to diety- in front of MIL. you can say that you read/ heard abt it for prosperity. And then based on this you can say that you have to go by very strict kitchen rules- not putting curd back- because you might have to offer raita to god next time etc, you get the point.
I hope you find a solution.
One example in my case- she touches raw fish/chicken and then touches all vessels/masala with fingers/even salt
she wants to be super clean and uses the same sponge(decaying) for dishes to clean wash basins puke puke