Spicy Thai Sweet Potato Soup with Coconut Milk

Ingredients:  
4 large sweet potatoes (around 2lbs) cut into chunks
4 cups chicken or vegetable broth
1-2 green chiles (seeded and sliced)
2-3 stalks of celery sliced
1 medium onion chopped
4-6 cloves of garlic minced
2 Tbs of grated fresh ginger
1 tsp of curry powder
red chili flakes to taste
1/4 cup of fish sauce (or vegetarian version of fish sauce available in some Asian Markets)
1 can of unsweetened coconut milk
4 cups of water
juice of one lime
lemon grass stalk (cleaned and bruised)
Thai Bird Chilies and Scallions for garnish

Directions: 

In a large soup pot, add 1 Tbs of olive oil.  Add the celery, onion and green chiles.  Cook for 2 minutes.  Then add the ginger, garlic and lemon grass.   Saute for another minute.  Add your sweet potatoes and cook for another 1-2 minutes. Then add your dry spices and cook for another minute.  Add the stock of your choice (chicken or vegetable), water and fish sauce or vegetarian equivalent.  Simmer for 30 minutes on medium high heat until all vegetables are very tender.   Then use either a hand immersion blender or a regular blender to make the soup smooth.  Add a can of coconut milk and simmer for another few minutes.  Check for the seasoning of salt in the dish here.  If you need more salt, add more fish sauce or salt as needed.  Turn stove off then add the juice of one lime or to taste.  Garnish with scallions and Enjoy.