Catalan (Catalonia), Spanish (Spain)
For matters which are completely unrelated to what was previously being discussed, English seems to like idioms related to animals:
This is a different kettle of fish.
This is a horse of a different colour.
In Spanish and Catalan, the pattern seems to be < food + container. >
Eso es harina de otro costal. ('That is flour from a different sack')
Això són figues d'un altre paner. ('Those are figs from a different hamper')
Are there any similar expressions in your languages? Do they mention animals, food or containers?