Can I buy cut-vegetables from a non-kosher store?
For instance, I sometimes find fresh onions prepacked and whole garlic peeled and packed, Those being “charif” (sharp foods), is there any prohibition on buying them?
They may not be purchased from a store without kosher supervision. If they were cut with non kosher utensil, then they have non kosher beliot absorbed in them.
For more on this topic see https://askhalacha.com/halacha/charif-sharp-food/.