Herbs are very easy to grow. Mint has to be the easiest. Add herbs to your organic feed, nesting boxes, etc. I learned a lot about herbs online and at www.timbercreekfarmer.com If you are thinking of getting into the chicken business, be sure to read everything you can in order to keep your flock healthy and free of chemicals.
I grow herbs in bulk so that during the Spring and Summer months I can feed mine fresh herbs and line their nesting boxes with them. I also dry herbs so that they will have them during the fall and winter months as well. My ladies are spoiled.
If you happen to not have a green thumb, their are several companies and health food stores that carry dried organic herbs.