1 tablespoon olive oil
2 garlic cloves, minced
1/2 tsp crushed red pepper flakes
1 medium bunch broccolini, cut into 1/2-inch pieces
Salt and pepper
3/4 c milk
4 oz country-style white bread, cut into 1-inch pieces
1/2 c grated Parmesan
4 thin slices pancetta
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 broccolini ; season with salt and pepper. Cook, tossing, until wilted, about 2 minutes; let cool slightly.
Meanwhile, whisk eggs, milk, 2 teaspoons salt, and pepper in a large bowl to blend. Add broccoli rabe mixture, bread, and Parmesan; toss to combine. Transfer to a baking dish. Top with pancetta.
Bake pudding until puffed, browned in spots, and set in the center, 45-55 minutes.