1. Preheat oven to 375 degrees Fahrenheit. Boil shells for a few minutes, not cooking thoroughly. Strain and fill pot back up with cool water and soak the shells until ready for use.
2. Mix spinach, tofu, nutritional yeast, oregano, and salt and pepper in a bowl or blender (the blender makes it creamier, like actual ricotta). Stir in mushrooms.
3. Rub some oil on the bottom of a 9 x 12 casserole dish. Fill each shell with ricotta-mushroom mixture and place in dish. Cover with half the can of pasta sauce.
4. Fill remaining half of pasta jar with water, shake, and pour into dish. Repeat with small amounts of water until jar is clean. The water helps the pasta cook all the way through.
5. Cook for 20 minutes or until pasta is cooked. Grate vegan mozzarella over the top and cook for ten more minutes.
Source of recipe: I created this recipe based on another pasta dish I make all of the time.