Dissolve bouillon cubes in 2 cups boiling water. Set aside.
Bring wine, 1/2 cup chicken broth, and next 3 ingredients to a boil in a small saucepan. Remove from heat, and let stand 30 minutes.
Melt butter in a Dutch oven over medium-high heat; add green onions and diced onion, and saute until tender. Stir in flour, and cook, stirring constantly, 5 minutes. Gradually stir in remaining 3 1/2 cups chicken broth and vegetable broth. Stir in wine mixture, quartered white mushrooms, and pepper, and bring to a boil.
Reduce heat, and simmer, stirring occasionally, 30 minutes. Cool slightly.
Process mixture, in batches, in a blender or food processor until smooth, stopping to scrape down sides. Return to Dutch oven, and cook over low heat, stirring occasionally, 5 minutes or until thoroughly heated. Garnish, if desired.
Note: We used Knorr Vegetarian Vegetable Bouillon.