You can find Garam Masala in Indian markets or at health food stores. It is a combination of coriander, cumin, cinnamon, clove, pepper, bay and several other spices. It is sold in bulk at many of the health food stores and is absolutely worth the effort to find.
¼ cup olive oil
¾ cup diced yellow onion
4-6 carrots, roughly chopped (peeling optional)
1 small yam, peeled and diced
sea salt and pepper to taste
¾ teaspoon garam masala, divided
3 cup vegetable stock
2 teaspoons fresh lime juice, or to taste
2 tablespoons sour cream or Greek yogurt, plus additional to garnish
1. Heat oil in a soup pot over medium heat. Add the onion, carrots, yam, ¼ teaspoon salt, ¼ teaspoon pepper, and ½ teaspoon garam masala. Cook for about 15 minutes, stirring frequently.
2. Add the stock and 1 cup cold water and raise the heat to high, Bring to a boil, then reduce the heat to a simmer, partially cover, and simmer until vegetables are tender, about 15 minutes. Remove from heat.
3. If you have an immersion blender, use it to puree the soup. (Otherwise, allow soup to cool slightly and then puree in batches in a blender. Return soup to pot.) Season with lime juice, to taste. And adjust the salt and pepper.
4. Mix sour cream or yogurt and remaining ¼ teaspoon garam masala in a small bowl. Swirl into the soup. Serve hot, garnished with additional sour cream or yogurt. If desired.