Prepare Spinach-White Bean Filling and Mushroom-Onion Filling. Preheat oven to 375 degree F. Lightly brush a sheet of phyllo with some of the melted butter. Top with another sheet and brush with more melted butter. (Keep remaining phyllo covered with plastic wrap to prevent drying.) Using a sharp knife or rotary blade cut the stacked phyllo in half lengthwise and then crosswise to make 4 equal rectangles.
Spread about 2 tablespoons of the bean filling in a 3/4-inch wide strip on a long side and to within 1 inch of short ends of each rectangle. Tightly roll the phyllo dough into a thin log, starting with the filled side. Brush seam side with butter. Place log, seam-side down, on a baking sheet; brush with butter and lightly sprinkle with sea salt.
Repeat with remaining bean filling and 4 more phyllo sheets. Repeat with mushroom-onion filling and remaining 6 sheets phyllo, using about 4 teaspoons filling per log and sprinkling logs with ground pepper.
Bake about 18 minutes or until logs are golden brown. Cool on on wire racks. Tie ends with chive strands. Serve warm or cool. Makes 24 logs.
Spinach-White Bean Filling
Thaw and thoroughly drain spinach; finely chop. Set aside. In a food processor bowl or blender container, combine beans, garlic, and water. Cover and process or blend until smooth. Transfer bean mixture to a medium bowl. Add chopped spinach; mix well.
In a large skillet heat oil until hot. Cook crimini and/or shiitake mushrooms, onion, and garlic over medium-high heat for 5 to 7 minutes or until mushrooms are tender and liquid has evaporated, stirring occasionally.