1. Preheat grill to medium-high heat.
2. Place bacon on grill rack; grill 1 1/2 minutes on each side or until browned. Remove from grill; set aside.
3. Sprinkle fish evenly with 1/4 teaspoon salt and 1/4 teaspoon pepper. Arrange fish on a grill rack coated with cooking spray; grill 4 minutes on each side or until desired degree of doneness.
4. Combine cabbages, parsley, and onion in a large bowl. Combine vinegar, oil, and mustard in a small bowl, stirring with a whisk; stir in mayonnaise. Add vinegar mixture, 1/8 teaspoon salt, and remaining 1/4 teaspoon pepper to cabbage mixture, tossing to coat. Top slaw with bacon just before serving with fish.
Wine note: The rich pink meat of ocean trout (or salmon) can easily handle a lighter red wine, especially when prepared with crispy smoked bacon. Bogle Pinot Noir 2008 ($14), from California's cool Russian River Valley, is medium-bodied with light berry and cherry flavors that won't overpower the dish, while a beam of bright acidity helps to balance the fish's healthful natural fats. --Jeffery Lindenmuth