Asparagus Soup

2 tbsp. butter
2 tbsp. olive oil
1 medium onion, finely chopped
1/2 tsp. salt
1/2 tsp. curry powder
1/4 tsp. ground ginger
zest and juice of 1 lemon
2 cups diced and peeled red pototaoes
3 cups chicken broth
1 cup "lite" coconut milk
2 cups 1/2 inch pieces trimmed asparagus
Ground pepper to taste
1/4 cup sour cream
1/4 chopped green onions
Melt butter and oil over medium heat. Add onion and 1/4 tsp. of salt, stirring often, until golden. Stir in curry powder, ginger, lemon zest and potatoes, stir, and simmer about 5 minutes. Stir in broth, coconut milk and aparagus. Bring to a simmer over medium heat, partially cover and cook until potatoes are tender, about 15 minutes.
Puree the soup in a blender (in batches) until smooth. Season with remaining salt and pepper.
Whisk sour cream, lemon juice and green onions in a small bowl and garnish with a swirl of it.