This simple strudel is made of roasted plums wrapped in a phyllo crust layered with pistachios.
Preheat oven to 400 degrees. Cut plums in half, and remove pits. Cut halves into 1-inch pieces. In a medium bowl, combine plums, lemon juice, sugar, and cinnamon, and toss well.
Divide plum mixture in half, and arrange in two 9-by-13-inch glass baking dishes. Roast, stirring occasionally with a wooden spoon, 25 to 30 minutes. Plum juices will reduce to a glaze during roasting. Remove plums from oven, and cool completely. Recipe can be prepared to this point 1 day ahead.
Unroll phyllo; cover unused portion with a damp kitchen towel as you work to prevent it from drying out. Cover work surface with parchment paper. Place a sheet of phyllo on parchment; brush evenly and lightly with melted butter. Cover with another sheet of phyllo, and brush again with butter. Sprinkle half the pistachios over this layer. Repeat process with two more layers of phyllo and remaining pistachios, then top with two more layers of buttered phyllo.
With the long side of the pastry toward you, spoon cooled plums along its length, 1 inch from the edge nearest you. Using the parchment to help you, gently roll up dough to encase the plums. Don't roll the pastry too tightly.
Brush strudel lightly with butter, and carefully lift it onto a large baking sheet. Bake until pastry is golden brown and fruit is bubbling, 35 to 40 minutes. Let cool on pan for at least 20 minutes; use two spatulas to transfer to a serving platter. Serve warm or at room temperature, cut into slices.
Frozen Greek phyllo dough is available in grocery stores.