Purple Ginger Soup

I made another puréed vegetable soup! This one is has a more subtle flavour than I usually go for with my curried vegetable soups. The ginger works nicely with the sweetness of the root vegetables. Serve with some yogourt. 
Brown:

4 small onions

0.5 head garlic

3 tbsp olive oil

Add:

4 knorr beef stock cubes

10 cups water

9 cups purple cabbage
2.5 cups beets
3.5 cups purple sweet potato
1 can turtle beans (540mL)

0.5 tbsp cumin

1 tbsp curry powder

1 tbsp fresh grated ginger

0.5 tbsp ground ginger

Makes 16 servings

Calories:     115

Protein:       4 g

Fat:              3 g

Sodium:       524 mg

Potassium:  106 mg

Fibre:           4 g

Sugar:          5g

Vitamin A:   84%

Vitamin C:   36%

Calcium:      5%

Iron:            8%