Homemade Spicy Merguez Sausages

"I’ve tried a number of Merguez recipes, from a variety of sources and largely I’ve wanted a little more poke! The following recipe is based upon many others but I’ve altered it to include a lot more garlic and harissa and also some sweetness with the sugar and cinnamon. This recipe packs a serious harissa punch and has enough garlic to keep Dracula at bay! Amazing on the BBQ or equally nice under the grill! Enjoy!"