I just got home from the store and opened this expensive block of cheddar to make dinner. There is a small spot of green fuzz on the corner, but the rest of the block looks completely fine. Do I just

and below the moldy spot to account for any possible penetration into the cheese. Be sure to angle the knife downward to avoid dragging mold spores across the surface.
After cutting away the mold, re-inspect the exposed area to ensure no traces remain. It’s also advisable to clean the knife with hot, soapy water before using it again to prevent cross-contamination.
6. When You Should Toss The Whole Block Instead Of Trimming
While trimming is often sufficient for hard cheeses, there are circumstances where discarding the entire block is advisable.