Adapted from The Border Cookbook, by Cheryl Alters Jamison and Bill Jamison (Harvard Common Press, 1995).

This is one delicious way to boost your immune system so you can avoid the flu, or to nourish yourself if you’ve caught it.

INGREDIENTS

* 3 whole heads of garlic
* 2 tablespoons vegetable oil, preferably peanut
* 1 medium onion, sliced thin
* 8 cups vegetable stock
* 1 to 2 dried or canned chipotle chiles
* 1/2 teaspoon salt, or more to taste
* 1/2 teaspoon cumin seeds, toasted and ground
* Juice of 1/2 to 1 lime
* Toasted thin flour tortilla strips and sliced avocado, for garnish (optional)

1. Preheat oven to 400 degrees.

2. Coat garlic with a thin film of the oil, reserving the remaining oil. Place garlic in a shallow pan and bake it until very soft, about 45 minutes. When garlic is cool enough to handle, peel all the cloves and reserve them.

3. Pour 1 tablespoon of the oil into a large saucepan or Dutch oven and warm over medium heat. Add the onion to the oil and saute until it’s softened and lightly colored. Transfer the mixture to a blender and add the reserved garlic. Puree, adding a little stock if necessary to blend the mixture.

4. Add remaining oil to the saucepan and warm it over medium-high heat. Pour in the blender mixture, being careful of any splatters, and saute it until it just begins to dry out and color. Add the rest of the stock, the chipotle, salt, and cumin, and reduce the heat to medium. Simmer the soup for 25 to 30 minutes, remove it from the heat, and add the lime juice.

5. Divide the tortilla strips and avocado between the bowls and pour the hot soup over them. Serve immediately.

Serves 6 to 8.