In a large pot of boiling salted water, cook the collard greens for 6 to 8 minutes, or until tender. Drain.
Add 2 cups of ice cubes and water to cover to a large bowl. Let ice melt slightly.
Transfer cooked collard greens to ice water to stop cooking.
Place several paper towels on a flat surface.
Carefully, without tearing, spread the greens onto the paper towels, “good side” down. If leaves are smaller or torn, it’s okay to overlap slightly. Pat each leaf dry. (If the leaves are extra tender, thin and clinging to each other, I use the smaller pieces as a "bandage" to create my own "full" leaf!
Combine garlic, 4 tablespoons of butter, shallots, ½ teaspoon of salt and ¼ teaspoon of pepper in a medium skillet. Add wine. Bring to a boil
Add mushrooms.
Over medium heat, cover and let cook, stirring occasionally for 12 minutes or until tender.
Spread some softened butter on the bottom and sides of a 2-quart ceramic or glass baking dish, preferably shallow.
Strain mushroom juices back into baking dish, reserving mushrooms.
Preheat oven to 450°F with rack on the second to last level.
To assemble bundles, spoon a ¼ cup mushrooms onto the middle of each collard green leaf.
Fold up each side and then roll each into a small “package,” completely enclosing the mushroom filling. Keeping in one layer, place seam side down, in prepared baking dish.
Add little bits of remaining Tablespoon of butter evenly over the bundles.
Heat in oven until mushroom filling is heated through and juices are simmering, 15-20 minutes.