The grocery items of the main database should not be deleted, as the many functions of the software depend on it and as you lose the associated synonyms and nutritional information. Instead, you should move to the extended list the items that you are not using, so that they are not displayed by default.
To recover the items you have deleted, there is an easy way, but it has a cost: you will lose every item that you have added to the database.
Here is how you can recover the original database:
0. Quit Shop'NCook if it is running.
1. Open your Shop'NCook data folder, that is folder "Shop'NCook Pro" in your Documents folder.
2. Open folder Templates.
3. Throw file T1.snctem to the trash (that is your database of grocery items). Don't touch to the other files in this folder...
4. Start Shop'NCook. The software will re-create the database from the default when it finds it is missing.