Lunch

Heat the oven to 400°F

Sprinkle the flour on the work surface

Unfold the pastry sheet on the work surface

Roll the pastry sheet into a 10x10-inch square, then cut into four (5-inch) squares

Heat the oil in a 10-inch skillet over medium heat

Add the onion and cook until tender, stirring occasionally, then remove from the skillet

Increase the heat to medium-high

Add the sandwich steaks and mushrooms to the skillet and cook for 3 minutes or until cooked through, stirring occasionally

Spoon 1/4 of the onion and 1/4 of the sandwich steaks and mushrooms on the bottom third of each pastry square and top each with cheese

Fold 2 opposite sides over the filling, roll up like a jelly roll, and brush the pastries with the egg

Place the pastries onto a baking sheet and bake for 20 minutes or until the pastries are golden brown

Let the pastries cool on the baking sheet on a wire rack for 10 minutes and then cut the pastries in half diagonally to serve