Puréed Winter Squash and Red Lentil Soup

Preparation

1. Step 1

   Heat oil over medium heat in large, heavy soup pot. Add onion and cook, stirring often, until tender, about 5 minutes. Add garlic, ginger, 1 teaspoon mustard seeds and 1 teaspoon cumin seeds and cook, stirring, until fragrant, 30 seconds to a minute.

2. Step 2

   Stir in turmeric, squash, red lentils and 2 quarts water. Turn up heat, add salt to taste and bring to a boil. Reduce heat to low, skim off foam, cover and simmer 35 to 45 minutes, until squash and lentils are tender. Taste and adjust salt.

3. Step 3

   Purée soup using an immersion blender or, working in batches, in a blender (pull a towel down over the top of blender to avoid hot splashes). Return to pot if using blender. Add black pepper, taste and adjust salt, and heat through.

4. Step 4

   Just before serving, heat butter over medium heat in a small skillet or saucepan and add remaining 2 teaspoons mustard seeds and 1 teaspoon cumin seeds. Cook, stirring, until seeds are lightly colored and fragrant, about 2 minutes. Stir into soup.

5. Step 5

   Serve with a generous dollop of yogurt and a sprinkling of cilantro if desired.