Yield: 8 servings.
4 medium sweet potatoes, peeled and cut into 1-inch cubes
2 tablespoons olive oil
2 tablespoons salted butter
1 cup onions, chopped
3 cloves garlic, minced
½ teaspoon nutmeg
½ teaspoon cardamom
1 tablespoon honey
2 teaspoons ground ginger
2 teaspoons salt
5 cups chicken stock
1½ cups heavy cream (or whole milk)
Greek yogurt or sour cream (optional)
Preheat oven to 400°. Place sweet potatoes on a cookie sheet lined with parchment paper. Drizzle 1 tablespoon of olive oil and sprinkle with salt.
Cook sweet potatoes for 30 minutes, or until edges are lightly browned.
In a stockpot, heat butter and remaining olive oil. Stir in onions. Cook onions for 5 to 10 minutes. Add garlic, nutmeg, cardamom, honey, and ginger. Stir onion-spice mixture and cook for 2 minutes. Stir in sweet potatoes, remaining salt, and chicken stock. Simmer for 20 minutes.
In small batches, blend soup in a blender until smooth. Add soup back to pot and stir in heavy cream. Simmer on low heat for 5 minutes. Serve hot and garnish with Greek yogurt or sour cream.