Preparation Cook collards in a large pot of boiling water with 1 tablespoon salt until just tender, 6 to 8 minutes, then drain. Transfer to a bowl of cold water, then spread leaves, undersides up, on paper towels, overlapping cut edges slightly, and pat dry. Bring wine to a boil with shallot, garlic, 4 tablespoons butter, 1/2 teaspoon salt, and 1/4 teaspoon pepper in a heavy medium saucepan. Add mushrooms and cook, covered, over medium heat, stirring occasionally, until tender, about 12 minutes. Butter a 2-quart shallow baking dish, then strain mushroom juices into baking dish, reserving mushrooms. Preheat oven to 450°F with rack in lower third. Mound about 1/4 cup mushrooms in center of each collard leaf. Fold leaves to enclose filling and arrange bundles, seam sides down, in 1 layer in baking dish. Dot with remaining tablespoon butter and cover with foil. Heat in oven until bundles are hot and juices are bubbling, about 20 minutes. Cooks’ notes:Bundles can be assembled and put in baking dish 1 day ahead and chilled. Bring to room temperature before heating.
Preparation Cook collards in a large pot of boiling water with 1 tablespoon salt until just tender, 6 to 8 minutes, then drain. Transfer to a bowl of cold water, then spread leaves, undersides up, on paper towels, overlapping cut edges slightly, and pat dry. Bring wine to a boil with shallot, garlic, 4 tablespoons butter, 1/2 teaspoon salt, and 1/4 teaspoon pepper in a heavy medium saucepan. Add mushrooms and cook, covered, over medium heat, stirring occasionally, until tender, about 12 minutes. Butter a 2-quart shallow baking dish, then strain mushroom juices into baking dish, reserving mushrooms. Preheat oven to 450°F with rack in lower third. Mound about 1/4 cup mushrooms in center of each collard leaf. Fold leaves to enclose filling and arrange bundles, seam sides down, in 1 layer in baking dish. Dot with remaining tablespoon butter and cover with foil. Heat in oven until bundles are hot and juices are bubbling, about 20 minutes. Cooks’ notes:Bundles can be assembled and put in baking dish 1 day ahead and chilled. Bring to room temperature before heating.