For the sauce:
- 1 1/2 pound cremini mushrooms, roughly chopped
- 1/2 pound shiitake mushrooms, roughly chopped
- 1 generous cup chopped onions
- 1/4 cup extra virgin olive oil plus more for keeping the noodles from sticking to each other
- 4 cloves garlic, chopped (about 4 teaspoons)
- 1 (6-ounce) can tomato paste
- 2 cups tomato sauce
- 1 (28-ounce) can crushed tomatoes (such as Muir Glen with basil)
- 1 cup water
- 1 tablespoon dried thyme
- 1/2 teaspoon red pepper flakes
- 1 tablespoon sugar
For the lasagne:
- 2 (10-ounce) boxes frozen chopped spinach, thawed and squeezed in clean towel of excess moisture
- 1 375g packet of Pangkarra Wholegrain Lasagne Sheets.
- 1 (15-or-16-ounce) container of ricotta cheese
- 1/4 cup chopped fresh basil
- 1/4 pound pecorino cheese (or Parmesan), grated (about 1 cup)
- 1 pound shredded mozzarella cheese (about 4 cups)
Sauté the mushrooms: Place mushrooms in a large (6 to 8 quart) sauté 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.
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.
Make the sauce: Add the olive oil to the mushrooms and stir to coat. Sauté 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 and 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.
Cook lasagne: as per the instructions on the packet.
Spread the one cup of reserved tomato sauce over the bottom of a large (preferably 10×15-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 lasagne sheets down over the tomato sauce, slightly overlapping. (For our 10×15-inch dish, we ultimately fit 3 layers of 6 noodles each)
Sprinkle half of the ricotta cheese over the noodles, and half of the defrosted, drained, and 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.
Repeat layers until dish is complete.
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.
Cover with foil and bake: 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 180 degrees for 25 minutes, then remove the foil and bake uncovered for an additional 25 minutes.
Take the lasagne 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.