When World Food Day was celebrated last Tuesday, the star—besides the ever-important mission to end global hunger—was the sweet potato. Turns out the simple vegetable is rich in nutrients, from fiber and calcium to potassium and Vitamin C. Did you know that 100 grams of the tuber has more potassium than a banana? In Africa, the veggie serves not only as food but as a cash crop to help pull families and communities out of poverty.

In honor of World Food Day, executive chef Paolo Neville, from the University of Colorado Anschutz Health and Wellness Center's Bistro Elaia, cooked up a perfect-for-fall sweet potato bisque. Bonus: There are just 159 calories in an eight-ounce serving. Here's how to make it at home.

Sweet Potato Bisque
(Yields 16 8-ounce servings)

2 tablespoons vegetable oil
1 cup yellow onions, diced
1 cup carrots, diced
10 cloves garlic, peeled
1/2 cup white wine
1 tablespoon dried thyme
2 pounds large sweet potatoes, peeled and diced
1 1/2 quarts vegetable broth
1/2 cup brown sugar
1 tablespoon nutmeg
2 tablespoons ancho chile powder
1 teaspoon salt
1 teaspoon white pepper
1/2 teaspoon cayenne
1 cup fat-free yogurt

Heat the oil in a large soup pot. Add the onions, carrots, and garlic cloves and sweat for 6 to 8 minutes, or until the onions are translucent. Add the white wine and reduce by half. Add the remaining ingredients, except the yogurt. Simmer for approximately 30 minutes or until sweet potatoes are cooked thoroughly. Transfer soup to a blender in batches and purée until smooth, adding the yogurt as you go.

Poblano-Basil Purée

1 roasted poblano pepper
1 ounce Italian parsley leaves
2 ounces fresh basil leaves
1/4 cup fresh lime juice
1/4 cup extra-virgin olive oil
1/4 teaspoon salt
1/4 teaspoon black pepper

In a food processor, purée the roasted poblano, parsley, and basil. Slowly add the lime juice and olive oil until incorporated. Season with salt and pepper.

Top each serving of bisque with a teaspoon of purée and serve.

—Image via Shutterstock