What is Harissa and where can it be found?

In addition to Whole Foods you can also find it a Sur La Table. Indeed, if you do a recipe search for "harissa" at Food52 you will find some good recipes.

Harissa is a hot red pepper paste used in North African cooking. You can buy it at most specialty food shops, and at Whole Foods. Or make your own: http://food52.com/recipes/6388-harissa