Vegetarian Spinach and Mushroom Lasagna - cremini mushrooms

Method

• Place mushrooms in a large (6 to 8 quart), saute pan on high or medium high heat.
• Stir them with a wooden spoon or shake the pan from time to time.
• You may hear them squeak.
• Sprinkle salt over the mushrooms.
• The mushrooms will sizzle and then start to release water.
• (Note that you are not adding fat at this point to the pan; this method of cooking mushrooms in their own moisture is called "dry sauteing.)
• Once the mushrooms start to release water into the pan, stir in the chopped onions.
• Cook until the mushrooms are no longer releasing moisture and the mushroom water has boiled away, about 5 minutes more.
• Add the olive oil to the mushrooms and stir to coat.
• Saute the mushrooms and onions for about a minute.
• Add the garlic and cook for another minute.
• Stir in the tomato paste, cook for a minute longer.
• Reserve 1 cup of the tomato sauce (it will go in the bottom of the casserole dish), and put the remaining cup of tomato sauce into the pot with the mushrooms.
• Add the large can of crushed tomatoes.
• Add one cup of water.
• Stir in the thyme, sugar, and red pepper flakes.
• If you are using dried basil instead of fresh, add it now.
• Bring to a simmer, then lower the heat and simmer on a low simmer, for 20 minutes.
• Once sauce is simmering, salt the boiling pasta water, and add the dry lasagna noodles to the boiling water.
• (The water should be at a vigorous, rolling boil.)
• Stir gently, making sure that the noodles are not sticking to each other.
• Set the timer for 8 minutes, or however long is indicated on the package of the noodles.
• Cook uncovered on a high boil.
• When the noodles are ready (al dente, cooked through but still firm to the bite), drain the noodles in a colander, and rinse them to cool them with cold water.
• As you rinse them, gently separate them with your fingers so they don't stick to each other.
• Prepare a couple large cookie sheets or baking sheets by spreading a tablespoon of olive oil over the baking sheets.
• Place the lasagna noodles on the sheets, gently coating them with a bit of that olive oil, and spreading them out.
• This will help keep them from sticking to each other while you finish the sauce and prepare the layered casserole.
• Turn off the heat on the stovetop for the sauce.
• Preheat the oven to 350F.
• Spread the one cup of reserved tomato sauce over the bottom of a large (preferably 10x15-inch) casserole dish.
• (If your casserole dish is smaller, you may need to add another layer as you go through this step.)
• Place a layer of lasagna noodles down over the tomato sauce, slightly overlapping.
• (For our 10x15-inch dish, we ultimately fit 3 layers of noodles, each layer with 6 noodles.
• Then we had 2 extra noodles on which to nosh.)
• Sprinkle half of the ricotta cheese over the noodles.
• Sprinkle half of the defrosted, drained, and excess moisture squeezed out spinach over the ricotta.
• Sprinkle half of the Mozzarella cheese over the spinach, and just a quarter of the pecorino cheese.
• Then spoon 1/3 of your mushroom sauce over the Mozzarella.
• Sprinkle half of the fresh basil over the sauce if using.
• Repeat the layering process.
• Place a second layer of noodles over the sauce.
• Spread the remaining ricotta, spinach, and Mozzarella over the noodles.
• Sprinkle another quarter of the pecorino along with the Mozzarella.
• Top with another third of the mushroom sauce and the remaining fresh basil.
• Layer your final layer of lasagna noodles over the sauce.
• Spread the remaining sauce over the lasagna noodles, and sprinkle with the remaining pecorino or parmesan cheese.
• Pull out a sheet of aluminum foil large enough to cover the casserole dish.
• Spread a little olive oil over the inside of the piece of foil (the side that will have contact with the lasagna).
• Place the foil over the casserole dish and crimp the edges.
• Bake at 350F for 25 minutes, then remove the foil and bake uncovered for an additional 25 minutes.
• Take the lasagna out of the oven when done and let it rest 10 minutes before cutting to serve.
• Once made, the lasagna will last a week in the fridge.