FILLING

In large skillet, heat oil over medium heat; cook pine nuts (if using), stirring occasionally, until nicely browned. Using slotted spoon, remove from pan; set aside. In same skillet, cook onion, sweet peppers, mushrooms, basil, salt, pepper and cayenne, stirring occasionally, for 10 minutes or until liquid from mushrooms evaporates. Remove from heat; stir in pine nuts. Cover and let cool to room temperature.

BEEF ROLL

Meanwhile, in large bowl, combine ground beef, bread crumbs, egg, tomato sauce, onion, garlic, basil, salt and pepper; mix well. Place meat mixture onto sheet of plastic wrap and spread into a 14 x 10 inch rectangle. Arrange prosciutto over meat leaving 1-inch border. Top with cheese and prepared filling. Using plastic wrap to help, roll up meat from short end. Pinch edges and ends to seal in Filling.

Bake on a greased foil-lined rimmed baking tray or line 9 x 5 inch (2 L) loaf pan with foil; grease. Place Beef Roll into pan, seam side down. Insert meat thermometer into centre of roll, avoiding bottom of pan. Bake in 350°F oven for 1 to 1 ¼ hours, until thermometer reads 160°F (70°C). Let stand 10 to 15 minutes. Use foil to help remove from pan; cut into 1-inch slices to serve.