Cut pastry to fit tops of 6 individual ramekins or one larger casserole. Bake on ungreased baking sheet at 450 degrees for 10-12 minutes.
Cook onion in butter until tender. Blen in flour, slat & broth all at once. Cook & stir until thick and bubbly.Pour into casserole(s) dish. Place baked pastry on top of hot filling just before serving.