Lasagna - from a friend of Emily's

A co-worker just gave me this recipe. I have not made it, but I've eaten it and its's good. It's a little messy but I will try to clean it up later- I used the following ingredients- 9 lasagna noodles cooked 1 jar of sauce (we used the tomato basil sauce from Trader Joes) We added half a roll of cooked sausage to the sauce Ricotta cheese (I think a standar is 15oz container) 1 egg 1/4 cup parmesan you mix the ricotta, egg and parmesan together and then I used two packages of mozarella cheese (well most...I didn't use all of the second) you just layer as follows 1.) noodles 2.) ricotta mixture (1/3) 3.) sauce (1/3) 4.) shredded mozarella cheese (however much you want) and you do that three times and then I just cook it according to the directions in the cookbook... sometimes we put mushrooms and spinach in the sauce