How to Make It
Preheat oven to 425°F. Heat 1 tablespoon oil in a large pot over medium-high. Add onion, carrots, and garlic; cook, stirring often, until vegetables are soft, about 6 minutes. Stir in coriander, chili powder, and turmeric and cook, stirring constantly, until fragrant, about 30 seconds. Stir in broth and lentils and bring to a boil. Reduce heat to medium-low; simmer, uncovered, until lentils are tender, about 15 minutes.
Meanwhile, place kale on a large rimmed baking sheet; sprinkle with teaspoon salt and drizzle with remaining 1 tablespoon oil. Massage kale until evenly coated; spread in an even layer. Bake, flipping once, until crisp and lightly browned, about 5 minutes per side.
Remove lentil soup from heat; transfer half of soup to a blender and process until smooth. Return blended soup to pot. Stir in lemon zest and juice, pepper, and remaining 1 teaspoons salt. Serve soup topped with crispy kale and several grinds of pepper.