Cook onion and garlic. Add bacon and cook for approx 3 minutes. Add diced mushrooms and cook until soft. Add cooked, drained spinach and mix well.
Take off the heat and mix in ricotta cheese. Set aside.
Cut lasagne sheets to size if needed. Spoon mixture across length of fresh pasta sheets and roll. Place into well greased lasagne dish. Continue till all mixture is used. Top rolled sheets with chopped tomatoes and then grated cheese and bake in the pre-heated oven for approx 30minutes or until hot.