To Serve (optional): Chopped coriander (cilantro), Thai sweet basil leaves, Greek style or regular yogurt, drizzle of coconut milk, steamed white or brown rice, crusty bread, naan, lime wedges for squeezing, etc.
Prepare the ingredients: Place the red split lentils in a fine mesh strainer and pick through for stones and sticks. Rinse well under cold water from the sink and set aside. Chop the red onion, garlic, red chilies, carrots and sweet potatoes as indicated in the ‘ingredients’ section. Wash the baby spinach. Pick the Thai sweet basil leaves off the stems (if needed and not already), then wash, pat-dry and set aside.
For the Thai Red Curry Lentil Soup:
Cook the chicken: Heat 1.5 tablespoons canola oil in a large Dutch oven or stockpot over medium-high heat. Add the ground chicken and season with ½ teaspoon kosher salt. Cook for 2-3 minutes, breaking up the clumps with a wooden spoon until just cooked through. Use a slotted spoon to transfer to a clean bowl.
Sauté the veggies: Add 1 tablespoon of oil to the Dutch oven and heat over medium-high heat. Add the red onion, carrots and sweet potatoes and sauté for 4-5 minutes until slightly softened. Add the garlic and red chilies and sauté to combine for another minute until fragrant.
Add the chicken and curry paste: Add the ground chicken back into the pot and Thai red curry paste. Stir-fry to combine until the paste has fully broken down and is fragrant – about 1 minute.
Build the soup: Add the red split lentils, chicken broth, water, and all of the spices and seasonings – the remaining 1 teaspoon of kosher salt, black pepper, ground cumin, coriander powder, turmeric powder, ground cayenne, ground cinnamon and Thai chili powder (if using). Stir to combine and bring to a boil over high heat.
Simmer: Lower the heat to medium-low. Cover and simmer for 20 minutes, or until the lentils have softened and the carrots and sweet potatoes are tender. (You can test for doneness by piercing them with a fork.) Uncover and taste the soup. Add more kosher salt or any of the other seasonings if needed.
Stir in the greens: Switch off the heat and stir in the baby spinach and Thai sweet basil leaves until just wilted.
To Serve: Divide evenly into bowls and top with chopped coriander, Thai sweet basil leaves, and a dollop of yogurt or drizzle of coconut milk if desired. Serve immediately with steamed rice, or naan or crusty bread for dunking and lime wedges for squeezing on the side.
Fresh Red Chilies: Feel free to use less or omit for a milder soup.
Thai Red Curry Paste: I use Mae Ploy Thai red curry paste in my home because I adore its authentic and spicier flavor. Other great authentic tasting Thai curry paste brands are Maesri and Nam Jai. If you’re after a milder flavor, Thai Kitchen and De Siam brand are good options. Start with 2 tablespoons if you are sensitive to heat and stir in more later if you like after simmering and tasting the soup. You can find it in packets, tubs, and cans in most large mainstream supermarkets, Asian and Thai grocery stores, or purchase it online.
Storing and leftovers. Leftovers can be stored in airtight sealed containers in the fridge for 4- 5 days. Reheat in the microwave for 1-2 minutes, stirring once in between, until hot throughout. Garnish as desired and serve.
To freeze and reheat: Once completely cool, transfer to freezer-friendly containers with a lid. Wrap in a sheet of aluminum foil for extra protection against freezer burn and freeze for up to 3 months. I recommend freezing servings in small individual containers so that you thaw only what you need. Plan a day in advance for when you want to have the soup again and thaw overnight in the fridge. Reheat in the microwave for 1-2 minutes, stirring once in between, until hot throughout. Then garnish as desired and serve.
See ‘Variations’ section in the post above if you’d like to customize this soup.