In a large bowl, combine the flour, baking powder and salt. Cut in butter until crumbly. Gradually add water, tossing with a fork until dough forms a ball. Turn onto a lightly floured surface; knead 10–12 times or until smooth.
Set aside a third of the dough. Roll remaining dough into a 15-by-11-inch rectangle. Transfer to an ungreased 11-by-7-by-2-inch baking dish.
In a bowl, combine turkey, cheese, soup, sour cream, onion, chilies and green onions. Spoon into crust. Roll out reserved dough; make a lattice crust. Place over filling; trim and flute edges. Bake at 400 degrees for 45–50 minutes or until crust is golden brown and filling is bubbly.