Mozzarella cheese can be a bit tricky to slice if you're aiming for perfectly round slices. We find that unflavored dental floss makes for clean cuts without squishing the cheese. (That's the method we used to slice the cheese in these photographs). Alternatively, you could try a specialty cheese cutter—or just use the sharpest knife you have. And don't worry too much: they'll taste the same, even if the slices aren't perfectly round.