Ah! Ça doit être un rouleau californien !
Hm, Monsieur est un connaisseur !
This is the first time I've seen sushi in the singular (mon sushi) instead of plural (mes sushi). Is there a rule about this?
Each piece is "un sushi", several pieces are "des sushis".
Cucumber is normally plural, so 'cucumbers in my sushi should be a epted
Considering the size of a piece of sushi compared to that of a cucumber, there can only be a small piece of cucumber in a piece of sushi, not several "concombres".