How to Make It
Melt the butter in a medium saucepan. Add the onion and cook over moderate heat, stirring occasionally, until golden brown, 8 to 10 minutes. Let cool.
For each brochette, thread 1 date half, 1 piece of onion and 1 lamb cube onto a skewer, then repeat; finish the brochette with another date half. Repeat until all of the ingredients are used up.
In a large glass baking dish, combine the olive oil with the cumin and harissa. Season the lamb brochettes with salt and pepper and add them to the dish, turning to coat them thoroughly with the marinade. Cover the brochettes with plastic wrap and refrigerate for at least 1 hour or overnight.
In a large bowl, cover the bulgur generously with warm water and let soak until tender, about 20 minutes; drain very well.
In another large bowl, whisk the orange and lemon juices with the olive oil and season with salt and pepper. Add the bulgur, tomatoes, cucumbers and mint and toss until thoroughly combined. Cover the tabbouleh and refrigerate for at least 1 hour.
Light a grill or preheat a grill pan. Season the brochettes again and grill them over moderate heat for about 3 minutes per side, until the lamb is medium rare. Mound the tabbouleh on a large platter. Arrange the brochettes on top and serve.
Harissa is a hot sauce made from red chiles and such spices as coriander and caraway. It is available in tubes, cans and jars at Middle Eastern groceries and specialty food markets.