2tablespoons minced ginger (from about 2 inches of peeled ginger root)
2teaspoons black or brown mustard seeds
1teaspoon ground turmeric
1teaspoon curry powder
½teaspoon ground cayenne, plus more to taste
½teaspoon cumin seeds
2carrots, peeled and sliced
2celery stalks, sliced
1large apple, preferably Granny Smith, peeled, cored and chopped
2tablespoons tomato paste
3tablespoons all-purpose flour
1pound boneless, skinless chicken thighs, cut into bite-sized chunks
1cup masoor dal (split red lentils)
6cups chicken broth or stock
1(14-ounce) can coconut milk
Juice of 1 lime (about 1½ tablespoons)
Directions
Warm the oil in a large pot or Dutch oven over medium-high heat. Add the onion, season with salt and cook, stirring occasionally, until translucent and shrunken, about 8 minutes. Add the garlic and ginger, and cook, stirring, until fragrant and softened, about 2 minutes. Add the mustard seeds, turmeric, curry powder, cayenne and cumin seeds, and cook, stirring constantly, until the mustard seeds pop and sizzle, about 90 seconds. Add the carrot, celery and apple, and cook, stirring, until just starting to soften, about 2 minutes. Stir in the tomato paste, then the flour, and cook, stirring well, to uniformly coat all the ingredients, about 2 minutes.
Add the chicken, masoor dal and chicken broth. Season lightly with salt. Bring to a boil, stirring to scrape up any browned bits sticking to the bottom of the pot. Reduce the heat to maintain a simmer.
Cover the pot and cook for 10 minutes, then uncover and simmer for 15 to 20 minutes more, until the chicken and carrots are tender, the soup is creamy, and the flavors have blended.
Stir in the coconut milk and squeeze in the lime juice. Serve in bowls topped with a dusting of cayenne, if desired.