Preheat the oven broiler.
Heat 1 tablespoon oil in a large skillet over medium heat. Add 1/2 teaspoon rosemary and the shallots and cook, stirring occasionally, until slightly caramelized, about 3 minutes.
Meanwhile, lay the fish in a single layer on a rimmed baking sheet lightly coated with nonstick cooking spray. Mix 2 teaspoons of the oil with the remaining 1/2 teaspoon rosemary, the lemon zest, 1/4 teaspoon salt and black pepper to taste. Rub over the tops of the fillets. Broil until just cooked through, 4 to 5 minutes.
Add the red pepper flakes and escarole leaves to the skillet. Toss to combine and then cover. Cook, covered, until the leaves are wilted and tender, about 4 minutes, uncovering once to toss. Uncover and stir in the raisins, vinegar and 1/2 teaspoon salt. Cook until any liquid has evaporated from the skillet, 1 to 2 minutes. Remove from the heat.
Season with salt and black pepper. Divide the vegetables among 4 plates, top each with a piece of fish and evenly drizzle with the remaining 1 teaspoon oil.
Per serving: Calories: 321; Total Fat: 10 grams; Saturated Fat: 2 grams; Protein: 39 grams; Total carbohydrates: 21 grams; Sugar: 11 grams; Fiber: 4 grams; Cholesterol: 92 milligrams; Sodium: 245 milligrams