Dice the chicken thighs into small, bite-sized pieces and set aside. Peel and finely chop the onion, garlic, and ginger to prepare for browning and flavoring.
In a skillet over medium heat, add a splash of oil and cook the chicken pieces for about 3-4 minutes until they develop a light golden color and smell toasty. This step builds a deeper flavor foundation for the soup.
Transfer the browned chicken to the slow cooker. Add the chopped onion, minced garlic, and ginger to the skillet and cook for 2 minutes until fragrant, then transfer everything to the slow cooker.
Add the rinsed red lentils, curry powder, chopped apple, and broth to the slow cooker. Stir everything well to combine, ensuring the spices are evenly distributed.
Set the slow cooker to low and cook for 6-8 hours, until the lentils are tender and breaking apart, and the chicken is fully cooked and tender. The house will fill with a warm, spicy aroma as it simmers.
Once cooking is complete, stir in the coconut milk and lemon juice. Taste and adjust seasoning with salt and pepper, then let the soup sit uncovered for 10 minutes to deepen the flavors.
Give the soup a gentle stir and check the consistency. It should be creamy with tender chicken pieces and a vibrant curry aroma. If it’s too thick, add a splash of broth to loosen it.
Ladle the Mulligatawny into bowls, garnish with chopped cilantro, and serve hot with a squeeze of lemon for extra brightness. Enjoy this fragrant, comforting dish that feels like a warm hug in a bowl.
