Add olive oil to sauté pan over medium high heat. Add chicken tenders, season with salt and pepper, and sauté until browned on first side. Add garlic after you have flipped the first side.
Remove chicken from pan when both sides are brown and allow to cool. Once cooled, chop into bite sized pieces.
Add canned tomatoes to the pan, after removing the chicken. And add mushrooms, if using, spices, along with salt and pepper to season.
Mix ricotta with egg, oregano, salt and pepper.
Place about 1 cup of tomato sauce on bottom of deep 9"x13" pan or lasagna pan. top with a single layer of pasta.
Top pasta with 1/2 of the ricotta and spread it over the pasta.
Top with another layer of pasta and then spread a generous layer of the tomatoes, sprinkle on the chicken and spinach and mozzerella. Finally top with a generous layer of parmesan cheese.
Top that layer with more pasta and repeat the last 3 steps.
There should be the perfect amount of everything to do 2 layers of each the ricotta and the sauce layer.
Bake at 350°F for 1- 1 1/2 hours until hot and bubbly.
Refrigerate leftovers promptly, when cooled. Leftovers last for 3-4 days in refrigerator.Leftovers can be frozen. I usually cut into individual pieces and wrap in aluminum foil.To reheat, thaw thoroughly in refrigerator. Open foil package and place on rimmed baking sheet. Heat in oven at 350°F for 30 minutes, until warmed through. Can be microwaved to reheat also. Remove from foil and place on microwave safe plate.