This is the 4903rd most frequent Russian word.
кашу
Porridge.
Here 'кашу' refers to a type of dish, typically porridge, commonly eaten for breakfast.
Я утром всегда ем кашу.
I always eat porridge in the morning.
In this usage, 'кашу' is part of an idiomatic expression meaning to create a complicated situation or mess.
Он заварил кашу, которую теперь надо разбирать.
He made a mess, which now needs to be sorted out.
This proverb implies that some things can always be improved, with 'каша' literally standing for porridge.