I am a from-scratch cook, simply because living out in the country, it's just easier to have the basic ingredients on hand so I can make a wide variety of recipes. When we first moved to our farm, access was so difficult that it was not unusual for me to get out to the store only once or twice a month. We bought in bulk, and to this day I retain some of that habit. I keep a good stock of basic cooking ingredients on hand.
For example, for baking I keep:
Flour (both self-rising and plain), sugar, baking soda, baking powder, salt, vanilla, cocoa, eggs, cinnamon and other spices, butter, and cooking oil. There is almost no limit to the recipes that can be made with these ingredients. Add a few nuts, raisins, oats or peanut butter and the range expands.
For general cooking:
Spray olive oil, rice, garlic, pepper, a variety of pastas, and dried or canned beans of many kinds.
To the above, add the vegetables, meats, fruits and potatoes from the cellar and freezer, and dinner possibilities are multiple choice. Can't forget tea and coffee either, and wine is a given, right?
Then there is the fresh stuff that for me is as important as the staples:
Apples, oranges, celery, onions, lettuce, tomatoes and carrots provide the bright punch of flavor during winter months we all need. In warmer weather, a lot of these are replaced or supplemented by the garden.
I'm curious as to what you consider to be the basics in your kitchen cabinets and fridge. What can you absolutely not cook without? What do you depend on for emergencies and quick dinners?