Process feta, sour cream, onion and pepper in food processor until smooth. Refrigerate sauce until ready to serve.
Heat broiler. Spray broiler-pan rack with nonstick cooking spray.
Thread pork cubes with zucchini and cherry tomatoes onto six 14-inch metal skewers.
Broil skewers 5 inches from heat 10 minutes, turning skewers over halfway through cooking.
While pork is broiling, cook the couscous according to the package directions.
To serve, spoon couscous onto serving platter; top with skewers; sprinkle with parsley. Serve sauce on the side. Makes 6 servings.