Preheat oven to 350 degrees F (176 C). Set out a large baking dish (9x13 inch or similar size) and lightly grease.
Begin by preparing/warming your sauce. Heat a large pot or rimmed 12-inch skillet over medium heat. Once hot, add oil and tempeh (or mushrooms — we used a mixture of both) and begin sautéing, stirring occasionally, for about 3 minutes.
Add coconut aminos (or worcestershire sauce), fennel (optional), and red pepper flake (optional) and continue sautéing for another 5 minutes. The mixture should be golden brown and well cooked.
In the meantime, if using noodles that require boiling, bring a large pot of water to a boil (otherwise skip this step). Once boiling, add a healthy pinch of salt and your lasagna noodles (or other pasta shape). Cook according to package instructions to achieve an al dente texture — tender with a little bite. Then drain and set aside. Optional: Drizzle pasta with a little oil to prevent sticking.
To the tempeh and/or mushrooms: Add your marinara sauce and stir to combine. Cook on low for about 5 minutes to marry the flavors. Then taste and adjust flavor as needed, adding salt to taste or red pepper flake for heat. Turn off heat and set aside.
Next, make your "cheese." Add macadamia nuts (or sub soaked cashews) to a food processor or a high-speed blender along with lemon juice, nutritional yeast, garlic powder, and sea salt and mix/blend into a loose paste.
Add lesser amount of water (1/3 cup or 60 ml as original recipe is written // adjust if altering batch size). Continue mixing, scraping down sides as needed. Then add more water — 1 Tbsp (15 ml) at a time — until a thick paste forms. I find I get the best texture results with a food processor, but a blender can work, too. It just generally requires more scraping and more liquid. For texture, you’re looking for a thick, spreadable soft “cheese.”
Taste and adjust flavor as needed, adding more nutritional yeast for cheesy flavor, salt for saltiness, lemon juice for acidity/brightness, or garlic powder for garlic flavor. Blend again to combine.
To begin assembly, add a thin layer of marinara sauce to your baking dish. Spread to ensure even distribution. Then add a layer of the cooked pasta noodles (or uncooked noodles if using no-boil). Top with 1/3 of your cheese mixture and spread into an even layer.
Add another layer of marinara sauce and use a spoon to spread over the cheese layer to coat. Then add another layer of noodles. Top with 1/3 of the cheese and spread into an even layer.
Add another layer of marinara sauce and spread into an even layer. Then top with another layer of noodles and remaining 1/3 of the cheese, and spread into an even layer. Top with another layer of marinara sauce and spread into an even layer.
Top with another layer of noodles and top with remaining sauce. Optional: Top with a sprinkle of vegan parmesan cheese.
Transfer to the middle rack of your preheated oven and bake for 40-45 minutes uncovered, or until the sauce is bubbly and/or the edges are browned.
Carefully remove from the oven and let cool 5-10 minutes before serving. Then slice, serve, and enjoy. We recommend garnishing with additional vegan parmesan cheese and fresh chopped basil or parsley. See notes for freezing instructions*!
*Sub 8 ounces tempeh for 3 cups (~300 g) shiitake mushrooms, thinly sliced. We added both tempeh and mushrooms to our sauce for more texture and nutrition. *To make this recipe freezer friendly, prepare as instructed. Once assembled, cover well and freeze up to 1 month. To bake, preheat oven to 350 degrees F (176 C), cover with foil, and bake for 30 minutes (if thawed) or up to 45 minutes - 1 hour (if frozen). Then remove foil and bake for another 5-10 minutes or until sauce is bubbly and hot. *Though not vegan, we have used Cappello's gluten free lasagna noodles and really enjoyed the texture and flavor! However, it does contain eggs so avoid if vegan or sensitive. *DIY Marinara Recipe. Nutrition information is a rough estimate calculated with all of the marinara sauce, all tempeh (no mushrooms), and whole wheat lasagna noodles, without optional ingredients.