"I came up with this soup when I wanted Thai food, but still wanted to eat light. This delicious and healthy soup is an easy way to eat vegetables (my husband hates vegetables, but loves this soup). I like to add a drizzle of Thai chili sauce and extra nuoc mam into my bowl of this soup. The exotic flavors will warm you on a cold winter day, and it is a healthy option when you are watching your weight. Add cooked shrimp to make this into a main meal."
Heat the sesame oil in a large cooking pot over medium heat. Add the onions and garlic and cook until the onions begin to turn translucent, taking care to not let them brown.
Add the red curry paste, carrots, broccoli, and apple and cook for about 5 minutes.
In the meantime, roughly chop the lemongrass and ginger. In a small pan, bring a cup of water to boil and add the lemongrass and ginger. Simmer over low heat for 10 minutes.
Strain the lemongrass mixture and add this to the vegetables in the large pot. Add the nuoc mam, fish stock, and any extra water if needed. The vegetables should be completely covered. Reduce heat to low and cover the pot. Cook for about 30 minutes.
When the vegetables are tender, remove soup from heat and add the coconut milk, lime juice, chili pepper, salt, and pepper. Using an immersion blender (or regular blender in batches)puree soup until smooth. Return to heat to bring it to desired temperature. Serve with Thai chili sauce and chopped green onions if desired.