Adding a flower window box outside your kitchen window is an awesome idea. But instead of flowers, plant your favorite herbs to pick fresh when you want to add them to the meal or sauce you are putting together.
Just about any herb, Dill, Thyme, Sage, Basil, you name it, will grow nicely in a window box, where they will be less likely to be bothered by insects or animals and be easy to take care of.
At Amazon there are all different shapes and sizes of window boxes you can get to fit your needs.
You can even add strawberries to your planter for a little extra enjoyment.