To make the matzo ball dough using a food processor or high-speed blender, blend the tofu and olive oil. Transfer the mixture to a large bowl and stir in the matzo meal, nutritional yeast, baking powder, onion powder, garlic powder, and celery seeds. Season to taste with salt and freshly ground pepper and stir well. Put the dough into an airtight container and refrigerate overnight.
Heat the olive oil in a large stockpot over medium heat. Add the onion, carrots, and celery and sauté for 5–6 minutes, until the onion is soft. Add the dill and stock, bring to a boil, then immediately reduce the heat to low and maintain a simmer.
Using your hands or a soup spoon, shape the dough into 2-inch (5 cm) balls. Carefully drop the dumplings into the soup, trying not to break them. Cover the pot and cook the soup at a low simmer for 40 minutes. Remove the pot from the heat, season the soup to taste with salt and freshly ground black pepper, and stir in the lemon juice. Garnish with the parsley and serve immediately.
Recipe courtesy of Vegan by Jean-Christian Jury. Get the book here: https://www.amazon.com/Vegan-Cookbook-Jean-Christian-Jury/dp/0714873918.