* Ras-el-hanout is a spice mix from North Africa which consists of more than 20 spices (some mixtures even consist of over 40 spices). There is no definitive composition that makes up ras-el-hanout, but commonly used ingredients are allspice, cardamom, cinnamon, turmeric, dry ginger, nutmeg, mace, fenugreek and black pepper. You can find ras-el-hanout in North African shops and organic food shops, but also in most supermarkets nowadays (the supermarket mixture usually consists of no more than 6 to 10 spices, but is perfectly okay to use in this dish).
** Harissa is a Tunesian hot chili pepper paste, the main ingredients of which are roasted red peppers, spices and (vegetable) oil. As you can imagine, it is very spicy, so you should use it with caution and never add too much at once. You can find harissa paste in North African supermarkets and organic food shops, but also in most supermarkets nowadays.
*** The skin of peppers is difficult to digest for some people, so you might want to peel the peppers.