This is the Maxis oatmeal, made available directly from the fridge (i.e. without having to use a microwave).
You need Custom Food Interactions 1.3 or later for this to show up. The original microwave oatmeal will continue to exist happily alongside this.
It is in the Quick Meal, Breakfast and Brunch pie menus, no skills or ingredients required; single servings only.
If you have the More Logical Cooking microwave snacks, the microwave oatmeal will be renamed to “Microwave Oatmeal” so you can tell them apart better; there is also a text override for the so-called cereal available so you won’t confuse that with oatmeal.
Localisation: This is using the original Maxis strings for all things Oatmeal, so should work in all languages.
XML Extractor, Notepad++, s4pe.