In cooking, I generally do not like the term "secret ingredient". Yes, it conjures up homey images of a grandparent's special spice or seasoning that makes their signature dish (my grandmother's secret is vodka in her pie crusts), but often it is a term used to describe one item that can cover all matters of sins to achieve something worth eating. I believe that a dish relies on the quality and care of all its ingredients, that one fantastic one cannot make up for the whole. I also believe that you should never not make a recipe just because you are missing one ingredient; searching for a replacement often leads to creativity and improvisation.
That being said, if there is one ingredient that can transform even the most humble of dishes, it's sesame oil. Dark and nutty, with a potent toasted flavor, all you need is a teaspoon or two in a stir fry to achieve vegetable heaven.
