In a large skillet, heat 2 tablespoon butter over medium-high heat. Add mushrooms and leek. Cook and stir until mushrooms are lightly browned and leek is tender, adding garlic during the last minute of cooking.
Stir in wine and cream; cook 1-2 minutes or until liquid is almost evaporated. Stir in herbs, salt and pepper. Remove from pan; cool completely.
Preheat oven to 375°. Place 1 sheet of phyllo dough on a work surface; brush with butter. Layer with 5 additional phyllo sheets, brushing each layer. (Keep remaining phyllo covered with a damp towel to prevent it from drying out.)
Spoon half of the mushroom mixture down center third of phyllo dough to within 1 in. of ends. Sprinkle filling with 2 tablespoons cheese. Fold up short sides to enclose filling. Roll up jelly-roll style, starting with a long side.
Transfer to a parchment-lined 15x10x1-in. baking pan, seam side down. Brush with butter. Repeat with remaining ingredients for second strudel. Bake 18-22 minutes or until golden brown. Let cool for 10-15 minutes before slicing.