Sautee onion, garlic and pepper flakes with vegetable oil in large stockpot until onion is tender. Add chicken stock, carrots and lemongrass and bring to boil. Reduce heat and allow to simmer for two hours or until carrots are soft. Remove lemongrass and puree with hand held blender or food processor. Strain soup and add coconut milk and cream. Season with salt and pepper.
Soup may be made in advance and is easily reheated. Recipe makes about 1 gallon.