Heat grill to medium. Season the ribs with 1 teaspoon salt and 1/2 teaspoon pepper. Place on grill, cover, and cook 20 to 25 minutes, turning often, until cooked through and tender.
Meanwhile, in a small bowl, combine the Worcestershire, mustard, and brown sugar. Baste the ribs with the sauce during the last 5 minutes of cooking.
In a large bowl, whisk together the sour cream, horseradish, vinegar, 1/2 teaspoon salt, and 1/4 teaspoon pepper. Add the cabbage, apples, and scallions and toss. Cut the ribs apart, divide among plates, and serve with the slaw.
Shortcut: If you're pressed for time, use pork chops, which require just 12 minutes of cooking. Turn them only once.