In a large pot over medium heat, add olive oil.
Add the onion and garlic and cook them for 2-3 minutes on medium heat, until the onions are translucent and they start to release their flavors.
To the garlic and onion, add the celery, carrot, and mushrooms. Cook them for another 2-3 minutes, while stirring occasionally.
Add in the vegetable stock, thyme, rosemary, nutritional yeast, salt and pepper, and stir them together.
Cook the soup until it comes to a boil.
Add the gnocchi according to the package instructions. Gnocchi will be cooked when they rise to the top.
Whisk together the cornstarch with 2 tablespoons of cold water to create a slurry. Add the slurry to the soup and stir to thicken.
Add in the spinach and cook for about 3 minutes, until the spinach softens.
Garnish with vegan parmesan cheese, and enjoy with some toasted bread!