In a large bowl, combine lamb, beef, bread crumbs, feta, parsley, garlic powder, ras el hanout, turmeric, and salt, mixing until well combined. Add egg, and stir until blended.

Form lamb mixture into 24 meatballs, each about the size of a walnut.

In a large skillet, heat ½ tablespoon olive oil over medium heat. Cook meatballs in batches, gently turning them at intervals to brown all sides and cook through— about 20 minutes for each batch.

Meanwhile, shave zucchini into long ribbons using a vegetable peeler. Lightly toss zucchini with salt and place in a colander to stand for at least 15 minutes.

When meatballs are cooked, remove from skillet and keep warm. Stir beef broth into skillet, loosening browned bits from bottom. Add garlic to broth, and heat to simmer; cook until broth is reduced by half.

Whisk lemon zest and remaining 1½ tablespoons oil into reduced broth. Add zucchini ribbons, and cook, gently tossing in pan juices, until slightly softened (but not limp), 6 to 8 minutes. To serve, arrange zucchini ribbons on each plate and top with meatballs.