Mulligatawny Soup Recipe

Name: Mulligatawny Soup Recipe
Prep time: 10 min
Cook time: 1 h 30 min
Total time: 1 h 40 min
Cuisine: British, Indian
Ingredients: 1/2 teaspoon whole mustard seeds; 1/2 teaspoon whole cumin seed; 1/2 teaspoon whole coriander seed; 2 tablespoons vegetable oil; Kosher salt and freshly ground black pepper; 1 pound (about 3 large) chicken thighs; 1 onion, finely chopped (about 1 cup); 1 medium carrot, finely chopped (about 3/4 cup); 1 celery rib, finely chopped (about 1/2 cup); 1 tablespoon curry powder; 3 medium garlic cloves, finely chopped (about 1 tablespoon); 1 inch piece fresh ginger, finely grated; 1 sweet potato, peeled and cut into 1/4 inch pieces; 1 apple, peeled and cut into 1/4 inch pieces; 1 plum tomato, cut into 1/4 inch pieces; 1/2 cup dry red lentils; 6 cups homemade or store-bought low sodium chicken broth, or water; Greek yogurt, to garnish; Finely chopped cilantro, to garnish; Red chili flakes, to garnish