Heat a pressure cooker and add onion. Cook, stirring, until onion is tender, adding water by the tablespoon to prevent sticking. Add the garlic and cook for another minute. Put the next 5 ingredients into pressure cooker and seal. Bring to high pressure and cook for 5 minutes. Remove from heat and release pressure manually. (Set manual setting on electric pressure cooker for 5 minutes then quick release pressure. If cooking without a pressure cooker, cook covered in a large pot until collards are tender, about 30 minutes.)
Add the beans, 2 cups of water or broth, and the remaining seasonings. Simmer for at least 20 minutes to allow flavors to combine. (Use saute or brown setting on electric pressure cooker on lowest temperature available.) While cooking, add additional water or broth if the soup seems too dry. Serve topped with vegan parmesan, if desired.