• First things first, make sure your packaged spinach is thawed. You can put the plastic part of the package in a bowl of warm water to help. Once the spinach is thawed, squeeze out all excess liquid by placing the spinach in a paper towel or clean dish cloth. Set aside for later.
• Start by cooking your lasagna noodles according to package directions in salted water. While those are cooking, you can begin preparing your mushrooms. Thinly slice the mushrooms and add them to a pan heated with 1 tbsp of olive oil over medium heat. Saute for about 8 minutes, or until done. Add the minced garlic to the pan, stir to combine, and cook for 30 seconds or until fragrant. Sprinkle with salt and set aside to cool.
• When the noodles are cooked to al dente (according to package directions), drain and toss with a drizzle of olive oil to prevent sticking.
• In a medium-large bowl, whisk together the package of ricotta cheese, a generous sprinkle of salt and pepper, and one egg. Then, add the cooled mushrooms and spinach. Stir to combine thoroughly.
• Preheat the oven to 400 Fahrenheit and begin assembling the lasagna.

Assembly

• In the bottom of a 9x13 baking dish, spread a thin layer of the sauce. Then lay down noodles to cover that. On top of the noodles, Spread a third of the ricotta filling, sprinkle generously with mozzarella, then lay more noodles on top. Top that with more sauce and repeat everything again.
• The order should be: sauce, noodles, ricotta filling, mozzarella, noodles, repeat. Finish with the sauce on top and a generous layer of mozzarella. It's important to cover all of the noodles because they will get hard while baking if they aren't covered.
• Once finished assembling, cover with foil and bake in the oven for 30 minutes at 400 degrees. After 30 minutes remove the foil and continue baking for another 10-15 minutes, until the top becomes golden and bubbly.
• Remove from the oven, carefully cut into slices, and serve. Enjoy!