Reduced Fat (15% Fat) cheese options can be purchased at most supermarkets. You can check whether a cheese is 15% fat by looking at the nutrition information panel. Look for the Total Fat per 100g. Anything with 15g total fat per 100g will be 15% fat.
If you cannot find a reduced fat cheese that is specifically 15% fat, don't worry! Any reduced fat cheese will do. The less fat it contains, the better.