Cook and drain noodles as directed on package; rinse with hot water and drain.
In a large skillet or Dutch oven, cook ground beef and Italian sausage until done; drain then add mushrooms, spaghetti sauce, and tomato sauce; simmer 10-15 minutes.
In a small bowl, blend egg and ricotta.
In the bottom of a 9x13" baking pan, spread layers of 1/3 of the sauce, then 1/3 of the lasagne noodles, then 1/3 of the ricotta mixture, and then 1/3 of the shredded cheese; repeat layers twice.
Cover tightly with aluminum foil and bake at 375° for 20 minutes; uncover and bake another 20 minutes; remove from oven and let stand 5-10 minutes before cutting.
NOTE: You can get by using 9 lasagne noodles, but I use 12 because I like to overlap them a bit ~ You also may vary the meats and use 1 pound sausage with 3/4 pound beef or whatever combination your family likes.