I’m trying to create some new food items and recipes, but I am having trouble accessing the Inventory image and the model. Can someone point me in the right direction?

You need to use a BSA Explorer to extract model and texture files, if you want to edit them.

Use the GECK to find out the location of said model (textures are assigned in NifSkope, not GECK), then extract it and use the aforementioned Nif utility to edit them. GECK also lists the location of the inventory texture image (interface/something).

What exactly are you trying to do, BTW?