In a large, heavy pot, heat oil over medium heat. Add the onions and saute until they become tender and start to brown, stirring often and adding a little water from time to time if they start to cook. Add the sugar and salt and stir briefly. Add the water, stock cubes, vegemite/miso and soy sauce. Cover and simmer for 30 minutes.
Add the wine and simmer uncovered for about 5 minutes. Taste for seasoning and add white pepper to taste. Place a piece of toast in each soup bowl and ladle soup over it. Sprinkle liberally with soy parmesan and serve hot.
From 'Nonna's Italian Kitchen', by Bryanna Clark Grogan.