wolf
I have to be mattir neder if I want to eat my fish with horseradish one week (since I normally do so without)?
You don’t have to be matir neder to start eating with chrein but if you do it for three meals in a row then you’ll have a problem if you want to stop because of maylin b’kedusha v’ein moridin.
Also remember that you don’t have to buy the most expensive condiments, hidur mitzvah is only up to a shlish miligav, vahamachmir al atzmo tovo olov bracha.
Also, does caviar have the din of fish? I would say maybe its like regular eggs but I can’t imagine eating caviar with meat.