Translation:We don't eat cheese with mayonnaise!
Both "de" and "le" are possible here depending on the original sentence. After a negative, only the indefinite articles (un, une, des) or partitive articles (du, de la, des) playing the role of direct object will change to "de". The definite articles (le, la, les) always remain the same. Therefore,
- On mange du fromage. -> On ne mange pas de fromage.
- On mange le fromage. -> On ne mange pas le fromage.
Mayonnaise is treated as an uncountable quantity requiring the partitive "de la" but it seems to me that cheese ought to be treated exactly the same in a sentence like this no? I'm thinking "du fromage" becoming "de fromage" in the negation instead of the given "le fromage". Am I thinking about this incorrectly? thanks in advance.