1. Heat oil in a thick-bottomed pot. Add onions and sugar and cook over very low heat until softened, stirring occasionally.
2. Add the flour, onion soup mix, soy sauce, and white wine and cook for 10 more minutes, until the onions are very soft.
3. Pour in the tomato juice and stir. Season with salt, pepper, and thyme. Cook for 30 minutes over very low heat, stirring occasionally.