To make Filling:
1. Put bulgur in medium bowl, and cover with 1 cup boiling water. Let soak until most of water is absorbed, about 15 minutes. Drain, and press out excess moisture.
2. Meanwhile, heat 2 tsp. oil in large skillet over medium-high heat. Add half of mushrooms, and cook, stirring occasionally, 4 to 6 minutes, or until tender and browned. Transfer to large bowl. Add 2 tsp. oil to skillet, and repeat with remaining mushrooms. Add remaining 2 tsp. oil to skillet, and reduce heat to medium-low. Add leeks, and cook, stirring often, 3 to 5 minutes, or until tender. Transfer to bowl of mushrooms.
3. Add bulgur, green onions, dill, parsley, lemon juice, and salt and pepper to taste to mushroom mixture; toss well. Let cool completely.
4. Preheat oven to 375F (if not making strudels ahead of time). Line 2 large baking sheets with parchment paper, or coat with cooking spray.
To make Strudels:
5. Unroll phyllo sheets onto clean, dry surface. Cover with plastic wrap and damp kitchen towel. Carefully lift one sheet of phyllo, and place on sheet of wax paper. Coat lightly with cooking spray. Layer another 5 sheets of phyllo on top, lightly coating each with cooking spray. Cut stack in half to make 2 squares. Keep phyllo stack covered while assembling individual strudels.
6. Place about 2/3 cup filling in center of one phyllo square. Bring 4 corners together, then press firmly along seams to seal. Lightly coat with cooking spray, and sprinkle with poppy seeds. Place strudel on prepared baking sheet. Repeat to make 8 strudels. (If doing ahead, tightly cover strudels with plastic wrap, and refrigerate.)
7. Bake 35 to 40 minutes, or until golden and crisp. To serve, pool Madeira-Mushroom Sauce on plates, and place strudels in centers of sauce.
