Preheat oven to 375°F Cut leek in half lengthwise; wash and trim, leaving 2 to 3 inches of green tips intact. Cut leek halves crosswise into thin slices. Place in small saucepan; add enough water to cover. Bring to a boil over high heat; reduce heat and simmer 5 minutes. Drain; reserve leek.
Melt butter in large skillet over medium heat. Add chicken; cook until chicken is golden, about 5 minutes. Add spinach and leek to chicken mixture,; cook 1 to 2 minutes longer. Remove from heat.
Spoon chicken mixture into pie crust. Sprinkle flour and cheese over chicken mixture. Combine half and half, eggs, brandy (Frangelica can be used in place of brandy), salt, pepper and nutmeg in medium bowl. Pour egg mixture over cheese.
Bake 35 to 40 minutes or until knife inserted into center comes out clean. Let stand 5 minutes before serving. Serve hot or cold.