Caramelized Onion, Mushroom, & Spinach Lasagna is delicious, light and easy to make! It is the perfect light and healthy meal for lunch or dinner, and great for vegetarians. Serve with a Classic Italian salad.
Course Main Course
Prep Time 1hour
Cook Time 45minutes
Total Time 1hour45minutes
1cupfreshly grated parmesan cheese
½cupfreshly grated romano
1teaspoonfreshly grated nutmeg
1teaspoonground black pepper
Caramelized Onions layer
2large sweet onionssliced
Pinchred pepper flakesoptional
16ounceswhite crimini mushroomssliced
1sprig thymeleaves strippped of stem
12ouncesfresh spinachwashed and rough chopped
1/8teaspoonfreshly grated nutmeg
½teaspoonground black pepper
12 - 16ouncesno-boil lasagna sheetsenough to fit 3 layers in a 10 x 14 pan
24ouncesgood qualityfresh Marinara (or Arrabbiata sauce), store bought or homemade
¼cupparmesan cheese for top
Preheat oven to 375 degrees. Spray a 10x14 inch casserole dish with cooking spray or grease with olive oil.
To make the ricotta filling
In a medium bowl, mix ricotta cheese, parmesan and romano cheeses, nutmeg, and pepper together until well combined. Set aside
To make the Caramelized Onions
Heat butter and olive oil on high heat in a large skillet. Add the sliced onions and cook on high heat for about 10 minutes, constantly stirring with spatula. Reduce heat to medium and continue cooking for 10 more minutes. Keep stirring to prevent burning on the bottom. Cook for 10 more minutes or until the onions are a deep golden brown. Add the balsamic vinegar to deglaze the pan. Transfer the mixture to a plate to cool.
Prepare the Spinach
Add 1 tablespoon olive oil to large skillet over medium high heat. Add freshly washed and chopped spinach, nutmeg, salt and pepper and toss. Cook for 5 -7 minutes or until just wilted. Set aside to cool.
Heat olive oil on high heat in a large skillet. Add the sliced mushrooms, salt, thyme, black pepper (and red pepper flakes if using) and mix. Cook on medium high heat for about 10 minutes, stirring occasionally to prevent sticking, until golden brown. Transfer to a plate to cool.
To assemble the casserole
Make first layer: Place ½ cup marinara on bottom of prepared 10 x 14 baking pan. Add one layer of lasagna sheets. Spread all of ricotta mixture over the lasagna sheets. Spread all of the carmelized onions on top of the ricotta layer.Make second layer: Add half a layer of noodles on top of the onions. Add ¾ cup marinara sauce over noodles. Place mushrooms evenly over the sauce. Sprinkle with handfuls of mozzarella cheese. Place cooked spinach evenly on top of mozzarella cheese. Sprinkle rest of mozzarella over spinach.Make top layer: Add layer of noodles on top of second layer. Spread rest of marinara sauce evenly over the top of the noodles. Sprinkle the top with parmesan cheese.
Cover the pan with foil. Bake at 375 degrees for 45 - 55 minutes or until the top is golden brown and the sides are bubbling. If needed, remove the foil from the pan the last 10 minutes to brown the top.
Remove from oven and allow to cool for 10 minutes.Cut in squares and serve immediately with extra Marinara on the side.