What is a "butter salt"?
One could have salted butter, but here the chef is putting the salt in the butter (this could also be said "The chef isn't giving salt to the butter" although it's a bit strange in English and I'd say "The chef isn't putting salt in the butter")
If the meaning is not to put salt in the butter, is there any particular reason of using a verb like "give" here, rather than "putte"?
Don't you have a verb "at salte" in Danish? In Swedish, the sentence would be "Kocken saltade inte smöret."
We use 'salt' as a verb too. In American English (or at least my dialect) the natural way of saying it would be "The cook did not salt the butter."