Harissa is a North African condiment made from cayenne peppers, olive oil, garlic and spices. Different brands have different levels of heat. I love the traditional harissa from Tunisia or Libya, it is the hottest version. If you have harissa from these countries, you may want to reduce the amount of harissa in this recipe for the sake of your tongue. Check the ingredients label; it will give you an idea of how hot it's going to be. Mild harissa will often have a mix of bell peppers in the ingredients.