In a large sauté pan over medium heat, sauté sausage, breaking up the meat to brown evenly. Remove from the pan to a large bowl.
In the same pan, sauté onions until softened. Add apples and sauté for 2 minutes. Add grapes and heat through. Combine sautéed onions and fruit with the sausage. Set aside to cool.
On a lightly floured work surface, roll out each sheet of pastry to measure 14 x 14 inches. Cut each sheet of pastry into 4 equal squares. Divide the filling and shredded cheese evenly among the 8 pastry squares. Fold in half to form a triangle and crimp the edges with a fork. Brush with beaten egg.
Bake the turnovers on a parchment-lined baking sheet for 20 minutes, or until golden brown. Serve warm. Makes 8 servings.
*Brands may vary by region; substitute a similar product.