This recipe is from Bon Appetit, April 2013 | Yields 4-6 servings
ONE Preheat oven to 350. Heat oil in a large skillet over medium heat. Add garlic and red pepper flakes. Stir until garlic is softened, about 30 seconds. Add broccoli rabe; season with salt and pepper [Not the amount above, only a sprinkle of salt and pepper.] Cook, tossing, until wilted, about 2 minutes; let cool slightly.
TWO Meanwhile, whisk eggs, milk, 2 tsp salt, and 1/2 tsp pepper in a large bowl to blend. Add broccoli rabe mixture, bread, and 1/2 cup Parmesan; toss to combine. Transfer to a 1 1/2-qt baking dish. Top with pancetta and the remaining 2 tbsp Parmesan.
THREE Bake pudding until puffed, browned in spots, and set in center, 45-55 minutes.