Coarsely grind cumin seeds, peppercorns, caraway seeds, red pepper flakes, and sugar in spice mill or with mortar and pestle until only a few whole spices remain.
Prepare a grill for medium-high, indirect heat (for a charcoal grill, bank coals on one side of grill; for a gas grill, leave one or two burners off). Oil grates. Thread lamb onto 6–8 skewers, leaving a small gap between each piece of meat. Season with salt, then sprinkle generously with spice blend, pressing it onto the meat with your hands to help it adhere if needed.
Senior editor Julia Kramer’s mother, Jill Weinberg, shared her family’s challah recipe with us—it is truly revelatory. All we can hope is that our faithful version comes close. (For best results, bake weekly for several decades.) This recipe makes two loaves, but it can easily be halved. This is part of BA’s Best, a collection of our essential recipes.