Greek yogurt seasoned with coriander, garlic and orange zest does double duty in this recipe. It’s used a sauce for serving and also creates a flavorful coating for chunks of pork loin. The yogurt-tossed pork is speared onto skewers and cooked quickly under the broiler; the char they develop adds flavor to the lean, mild-tasting meat. Serve with a rice or orzo pilaf and a simple leafy salad.