Instructions
Preheat the oven to 425 degrees.
Place the butter and olive oil in a sauté pan over medium heat.
When the butter has melted and looks foamy, add the onion and mushrooms and cook for or until vegetables are softened and the pan liquid has evaporated.
Add the wine, turn the heat to high and bring the liquid to a HYPERLINK "http://www.foodterms.com/encyclopedia/boil/index.html" boil.
Cook until the wine has evaporated.
Remove the pan from the heat and season the ingredients with the dill and some salt and pepper to taste.
Roll each pastry sheet into a 12-inch square on a lightly floured surface.
Cut each in half, to make four 12-inch x 6-inch rectangles.
Spoon the onion-mushroom filling on top of each of four rectangles, leaving a border of 3-inches at the top and bottom edge.
Place one salmon filet over the vegetables on each rectangle.
Brush a film of beaten egg around the perimeter of each puff pastry sheet.
Fold the short edges over the fish, then wrap the fish by folding the long edges around the fish to seal it completely, crimping the edges to seal them well.
Place the packages seam side down on a cookie sheet.
Brush with more egg.
Bake for or until golden brown.
Makes 4 servings