4 green onions, cut in half lengthwise, then cut into thin long strips
Heat beef pot roast with gravy in microwave according to package directions. Remove pot roast from container; discard gravy. Shred pot roast in large bowl with 2 forks; stir in cheese. Set aside.
Heat oven to 400°F. Spray 2 metal baking sheets with nonstick cooking spray. Unfold each puff pastry sheet onto lightly floured surface.
Cut in half with sharp knife or pizza cutter to make four 10 X 4-3/4 inch rectangles.
Working with 1 rectangle at time, place a long side in front of you. Place 1/4 of the beef mixture onto pastry, leaving a 1/2 inch border on the long side closest to you. Lay 1/4 of the green onion strips lengthwise over beef mixture. Roll up pastry jelly-roll fashion starting with long side opposite you. Brush water along border and seal pastry. Repeat with remaining pastry, beef mixture and green onions.
Cut pastry rolls crosswise into 1/2-inch thick slices, forming pinwheels. Arrange 1 inch apart on prepared baking sheets. Bake in 400°F oven 15 to 17 minutes or until golden brown, rotating pans halfway through baking. Transfer pinwheels to wire rack; cool slightly. Serve warm.