Heat soup pot over medium heat. Add onions and oil. Saute until tender. 

Add broccoli and broth, cover and simmer for 10 minutes or until broccoli is tender.

Pour soup into a blender or use an immersion blender to puree the soup.

Place a small saucepan over medium-heat, add 2 tablespoons oil, stir in flour and add soy milk. Stir until thick and bubbly, and add to soup. 

Season with salt and pepper to taste and serve.

This soup an actually be made ahead and reheated or kept hot on the stove.  Because you are using soymilk instead of regular milk it doesn't curdle.

Garnish with Non - Dairy sour cream if desired.