Heat the oven to 400°F. While the oven heats, spread the pistachios in a small oven-safe frying pan and toast in the oven until fragrant and beginning to brown, about 5 minutes. In a small bowl, combine the ground lamb and the ground beef with sausage spice mix. Set aside.

Peel the red onion and cut into 1/4-inch thick rounds and break apart into rings. Place the onion rings and the cauliflower on a sheet pan. Drizzle with about 1 tablespoon oil and toss to coat. Season with salt and pepper. Bake until the vegetables are soft and beginning to caramelize, about 15 minutes.
Meanwhile, make the sausages.

Shape the sausage mix into 4 patties. In a grill pan or a 12-inch cast-iron skillet over medium high heat, warm 1 tablespoon oil until hot but not smoking. Add the sausage patties and cook until well-browned, about 5 minutes on each side.
While the sausage cooks, prepare the relish.

• Chop the olives.
• Cut the tomatoes in half.
• Mince the preserved lemon.
• Chop the mint.

In a bowl, combine the olives, tomatoes, preserved lemon and mint with the pistachios. Add 1 tablespoon oil, season with salt and pepper.

Pick the dill fronds from the stems. Chop the dill and toss with the roasted cauliflower and onion. Transfer the sausage patties to serving plates. Top with the relish and serve the roasted vegetables alongside.