In a small bowl, combine the cumin, coriander, smoked paprika, garlic powder and onion powder. Add the spice mix to the lamb mince and mix thoroughly. Season with salt and black pepper.
Divide the mince into four equal portions and shape into balls (approximately 150g each).
In a separate bowl, mix together the mayonnaise, harissa paste, lemon juice and a pinch of salt to make the harissa mayonnaise.
Lightly oil the griddle if needed. Place the lamb balls onto the hot surface and leave for about 10 seconds.
Gently press each ball down to form thick patties. Cook for 3–4 minutes until well browned.
Flip and cook for a further 3–4 minutes until cooked through.
Lightly toast the hot cross buns on the griddle.
Assemble the burgers by spreading hummus on the bottom bun, adding a double stack of lamb patties, topping with pickled red cabbage, a spoonful of harissa mayonnaise, and a sprinkle of pomegranate seeds.
Place the top bun on, press lightly, and serve immediately.