In a 9 x 13 glass baking dish place enough of the sauce to cover the bottom.(Adding the sauce to the pan before meats and mushrooms allows for a flat surface to build from.) Then cook meats and add to spaghetti sauce mixture along with package of mushrooms.
Start your fist layer by placing 4 sheets of lasagna noodles, top with half of the ricotta cheese, half of the sauce, and a layer of mozzarella cheese.
Repeat layers until pan is full.
Bake covered with foil for 1 hour. Remove foil and bake for about 10 minutes to allow top cheese to brown. Let sit for at least 5 to 10 minutes to allow for cooling( please don't skip this step if you do you will have a lasagna mess instead of clean slices.)