Step 1: Check the cupboard

Picture of Check the cupboard
I had a can of mixed beans, and a can of Northern beans.  
I also had an onion and a shallot!  (I later replanted the bottom of the shallot to grow a new one!)
You'll want some kind of oil to saute your onions
If you have vegetable stock or some such thing, awesome for you!  You can just use water.
I was lucky enough to find a bouillon cube tucked away in the cupboard!

If you've got more stuff you want to add in - that celery wilting in the bottom drawer, some of those baby carrots in the back of the fridge - whatever you find, put it in there!