Brown the sausage crumbles in a separate cast iron pan or in the same large stock pot or dutch oven you’ll make the soup in. Cook over medium heat with a small amount of oil, if needed, until browned, about 6 to 7 minutes.
If cooking the sausage in a separate pan you can start on the soup or once the sausage is browned, remove it from the dutch oven or stock pot into a dish and set aside.
Add shitakes to the stock pot or dutch oven over medium heat and cook down and brown for about 6 to 7 minutes. Do not add any olive oil to the pan at this point. I like to cook the mushrooms in a mostly dry pot with their own juices that evaporate. Once shrunk to about half the volume stir in olive oil, onion, celery, and carrot and cook for 4 to 5 minutes until softened. Stir in garlic, thyme, and oregano, and cook another 2 to 3 minutes. Stir in bouillon paste to coat all the vegetables well and then add the hot water.
Break up lasagna into the pot and bring to a boil. Stir occasionally to ensure the noodles don’t stick together. Cook for about 8 to 9 minutes, lower heat to medium and then add nondairy milk, sour cream, cream cheese, parmesan, and spinach. Cook another 10 minutes or until lasagna is cooked to al dente and the soup is thickened slightly. Add sea salt and ground black pepper to taste. Stir in I added 1 teaspoon of each, but adjust to your tastes and it will depending on the bouillon you use.
Add half the parsley at the very end as well as the cooked sausage. Serve immediately and garnish with more parsley for serving, and a sprinkle of extra vegan parmesan if desired.