1. Preheat the oven to 375°F.
2. On a work surface, place a sheet of phyllo dough flat. Brush with butter on the entire surface.
3. Place a second sheet on top, making sure to align the edges. Repeat this operation until three sheets are stacked.
4. Cut into 8 equal squares and mold into a muffin tin. (Do not grease the tin.)
5. Bake for 4 minutes until the dough is golden brown. Reserve.
6. Pour a small amount of water into a saucepan, add the tomatoes, cover, and cook over medium heat. Drain and place on paper towels. Cut the dried tomatoes into fine julienne.
7. In a bowl, mix the cooked mussels, dried tomatoes, and green onion. Add the olive oil and rice vinegar. Season with salt and pepper. Sprinkle with chives and mix.
8. On a bed of lettuce, place the cooled phyllo cup and fill with mussels. Serve as an appetizer.