1 large leek: $2.00
1 large sweet potato: $1.50
1 pound potatoes: $1.00
1/2 pound cabbage: $0.75
2 carrots: $0.50
Pantry items: Chicken or vegetable stock, butter, salt, pepper, yogurt, olive oil.
Total cost (for 2 portions): $5.75
This soup was born of a moment of panic last week when the refrigerator had gotten perilously bare. A single leftover baked sweet potato, old vegetable odds and ends, stock made from Sunday's chicken carcass, and some leeks I had splurged on without having anything special in mind. I love potato leek soup, so why not sweet potato leek?
I roasted potatoes, carrots, and cabbage in a 400°F oven while the soup simmered and had a bright and tasty lunch ready in under an hour. Like butternut squash soup, this one was richly smooth and creamy-tasting despite its lack of cream. I had worried it might be bland, seasoned with salt and pepper only, but it was delicious. If it is bland for your taste, you might add anything you'd use with squash or sweet potatoes: cumin, cinnamon, ginger, or garam masala, for instance.
If you don't have a pre-baked sweet potato, use a raw one and simmer it in the stock until tender. If you don't have a leek, try an onion. And if you don't have chicken or vegetable stock, you can use bouillon powder or miso paste. I often make soups with water only, but for something this simple you need a little more flavor in the liquid base.
- 1 tablespoon butter
- 1 large leek, white part only, cleaned and chopped
- 1 large sweet potato (about 1 1/4 pounds), peeled and chopped into 1-inch chunks if raw, insides only if pre-baked
- 3 cups chicken or vegetable stock
- Plain yogurt for garnish (optional)
Heat the butter in a saucepan over medium heat. When the foam subsides, add the leek pieces and cook until they are very tender but not starting to brown, about 10 minutes (turn the heat down if necessary).
Add the sweet potato and 1/2 teaspoon salt and stir with the leeks for a minute or two. Then pour in the stock and bring to a boil. Simmer until the sweet potato pieces are completely tender, 20-30 minutes. (If you are using a pre-baked sweet potato, simmer for about 10 minutes.) Puree the soup, taste for salt and pepper, and reheat if necessary. Garnish with a spoonful of yogurt and serve.