Combine the cream, vinegar, Worcestershire, blue cheese, and garlic powder. Taste, and add salt and pepper to your taste, or a splash of water if the dressing is very thick.
FOR THE SALADS
Preheat the oven to 400F. Arrange the tomatoes cut-side up on a baking sheet, and roast for 20 minutes or until slightly dark and wilted.
Meanwhile, crisp the pancetta in a skillet over medium-high heat for about 5 minutes, then drain on paper towels.
To assemble, arrange the wedges with green onions, roasted tomatoes, pancetta, and capers. Drizzle with the dressing and crack extra pepper over top, if desired.