Ingredients

• 3 tablespoons vegetable oil
• 2 tablespoons unsalted butter
• 1 1/2 pound butternut squash, peeled and cut into 1/2-inch pieces
• 1 large onion, chopped
• 1 carrot, chopped
• 1 celery rib, chopped
• 2 garlic cloves, minced
• 2 tablespoons minced peeled ginger
• 1 tablespoon curry powder (preferably Madras)
• 1 cup red lentils, picked over and rinsed
• 2 quarts water
• 1 teaspoon fresh lemon juice, or to taste
• 1/2 cup chopped cilantro
• 1/2 cup vegetable oil
• Accompaniment: cooked basmati rice

Instructions

1. Heat oil with butter in a large heavy pot over medium heat until foam subsides, then cook squash, onion, carrot, celery, garlic, ginger, and 1 teaspoon salt, stirring occasionally, until vegetables are softened and beginning to brown, 15 to 20 minutes.
2. Stir in curry powder and 1/4 teaspoon pepper and cook, stirring frequently, 2 minutes.
3. Add lentils and water and simmer, covered, until lentils are tender, 25 to 40 minutes. Stir in lemon juice and season with salt and pepper.
4. Make cilantro oil: Purée cilantro, oil, and 1/2 teaspoon salt in a blender. Serve soup drizzled with cilantro oil.
5. Purée cilantro, oil, and 1/2 teaspoon salt in a blender.
6. Serve soup drizzled with cilantro oil.