In a large bowl, combine the ground meat with salt, paprika, pepper, ground fennel, and harissa.
Drizzle in the olive oil and mix until fully incorporated.
Cover and refrigerate the mixture overnight to let the flavors meld before stuffing.
Stuff the seasoned meat into the lamb casings.
Hang the sausages in the refrigerator and let them dry for 36 hours.
Grill the merguez over hot coals or sear them in a skillet.
Notes
To keep the sausages tender and juicy, avoid overcooking them.Harissa Samia, sold in 100 g jars, is ideal for this recipe. It faithfully captures the taste of traditional homemade Tunisian harissa and contains only dried ground chilies, salt, and plenty of garlic.