Green Onion Casserole

Preheat oven to 350 °F. and butter a 1 1/2-quart shallow baking dish. In a kettle cook scallions and garlic in butter over moderate heat until scallions are softened, about 20 minutes. Stir in cream and 1/4 cup Parmesan and transfer to baking dish. In a skillet heat oil over moderately high heat until hot but not smoking and sauté bread crumbs, stirring, until golden brown, about 3 minutes. Transfer bread crumbs to a bowl and cool. Add remaining 1/4 cup Parmesan and season with salt and pepper. Top casserole with bread crumb mixture. Casserole may be prepared up to this point 1 day ahead and chilled, covered. Bring casserole to room temperature before proceeding. Bake casserole, uncovered, in middle of oven until hot, 15 to 20 minutes.