1. In a skillet over medium heat, melt the butter. Add the pears and saute, stirring, for 2 minutes. Add 2 tablespoons of the sugar, and cook until the pears are lightly caramelized, about 5 minutes. Set aside to cool. In the bowl of a mixer, combine the caramelized pears with the flour, sesame seeds, the remaining 2 tablespoons of sugar, heavy cream, pistachios and lemon zest. Mix Well. Cut the phyllo dough into 18 strips, 4x12 inches each. Place a teaspoonful of the pear mixture at one end of each strip, and fold the corners over to make triangles. Continue to fold them like you would fold a flag until there is no remaining dough.
2. In a large skillet over medium-high heat, warm 2 inches of vegetable oil. Carefully lower the triangles into the hot oil, and fry until golden, about 3 minutes. Remove using a slotted spoon, and drain on paper towels. Dust with powdered sugar, and serve immediately.
