Heat a large pot with oil on medium heat. Once hot, add the chopped onion and cook for 3 minutes. Add the garlic and cook for an additional 1-2 minutes.
Add the vegetable broth, lentils, canned tomatoes, tomato paste, and italian seasoning. Stir and bring soup to a boil.
Once the soup is boiling add the salt and pepper. Slowly, break the lasagna noodles into bite sized pieces and add them to the soup. Cook for 7-8 minutes or until the noodles are completely cooked.
Add the lemon juice, plant milk, nutritional yeast, fresh spinach, and stir. Remove the pot from the heat.
Taste soup and add additional seasoning (salt, pepper, or italian seasoning) if needed.
Divide into soup bowls and serve.
Leftovers can be kept in the refrigerator in an airtight container for 3 days.