Place the lamb cubes, olive oil, cumin, oregano, paprika, kosher salt and black pepper into a large bowl or resealable bag along with the bashed garlic cloves. Mix well so that the lamb is thoroughly coated. Leave in the fridge to marinate for at least 4 hours, preferably overnight.
1 ½ lb boneless lamb leg or shoulder, 1 ½ teaspoon dried oregano, ¾ teaspoon cumin, ¾ teaspoon paprika, 1 ½ teaspoon kosher salt, 4 tablespoon extra virgin olive oil, 3 cloves garlic, ¾ teaspoon freshly ground black pepper