Preheat oven to 350 degrees.
Sauté mushrooms in a skillet until browned, about 8 minutes. Season with salt, pepper and 1 tsp Italian seasoning at the end of cooking time.
In a small bowl, mix together ricotta cheese, eggs, 1 tsp salt, 1/2 tsp black pepper and 1 tbsp Italian seasoning.
In a 9 x 13 dish, ladle in a layer of tomato sauce. (note: I use homemade sauce and it makes a big difference in the flavor. My recipe is above).
Add a layer of the noodles, slightly overlapping (typically 4 noodles) over the sauce.
Spoon 1/2 the ricotta mixture on top, spreading it out to an even layer.
Sprinkle on 1/3 of the bag of cheese, then a 1/2 the spinach and 1/2 the mushrooms.
Repeat steps 4-7.
For the last layer, add the lasagne sheets, the last of the sauce and the rest of the cheese.
Bake at 350 for 30-40 minutes covered in foil. Uncover and cook for an additional 10, broiling for 2 minutes at the end for browning, if desired