In a large bowl combine ground lamb and chopped fat (if using). Add harissa, paprika, ground cumin, ground coriander, ground fennel, cayenne, kosher salt, black pepper, and minced garlic. Mix thoroughly with clean hands until spices are evenly distributed and mixture becomes slightly sticky, about 1–2 minutes. Fold in chopped cilantro.

Form sausages

Divide the mixture into 6 equal portions (about 2.7 oz / 75 g each). With lightly oiled hands, roll each portion into a sausage shape roughly 3–4 inches long and 1 inch thick. Press ends to seal and keep a consistent thickness for even cooking.

Cook the sausages

Heat 1 tablespoon olive oil in a large skillet over medium-high heat. When the oil shimmers, add the sausages without crowding the pan. Cook for 3–4 minutes per side, turning every 2–3 minutes so they brown evenly and reach an internal temperature of 160°F (71°C). Total cooking time is about 10–12 minutes depending on thickness. If they brown too quickly, reduce the heat to medium and finish cooking. Transfer sausages to a plate and let rest for 3 minutes before serving.

Sumac Onions & Accompaniments

Make sumac onions

While the sausages cook, place thinly sliced red onion in a bowl. Add 1 tablespoon lemon juice, 1 teaspoon olive oil, and 1 teaspoon sumac. Toss to combine and season with a pinch of salt to taste. Let sit for at least 5 minutes to soften and absorb flavors. Stir in chopped mint or parsley just before serving.

Prepare yogurt dip

Spoon 1/2 cup plain yogurt into a small bowl. Stir in a pinch of salt and, if using, 1 teaspoon chili oil or a pinch of crushed red pepper. Taste and adjust seasoning. Transfer to a serving bowl.

Assemble and serve

Place rested merguez sausages on a serving board or plate with sumac onions and yogurt dip. Serve with mini pitas, crusty bread, or crackers. To eat, split a sausage and top with sumac onions and a dollop of yogurt. Garnish with extra chopped herbs and a light dusting of sumac if desired.