Preheat oven to 350°F.

Place one sheet of thawed Fillo dough on a greased cookie sheet. Spray dough with cooking spray. Place another sheet of dough on top. Continue with this pattern until you have 6 sheets of dough. Do not spray the top sheet. Cut into 8 squares with pizza cutter. (My sheets were 9" 14", so my "squares" were actually rectangles and measured about 3.4"x4.5" each.) Press each square into a muffin pan cup. Make 24 pastry cups with this method, then bake them for 9-12 minutes or until light golden brown. Do not overbake because they will go back in the oven once they are filled.

Meanwhile, make the casserole. Place Campbell's Cream of Mushroom Soup in an oven safe bowl or dish. Add Swanson's Chicken Broth and pepper. Whisk until smooth. Stir in drained beans until completely combined. Bake in oven for 25 minutes. Scoop into pastry cups. Add French's Crispy Onions on top and bake for 5 minutes more. Serve warm.