Tamarind Sweet Potato Bisque

It's been a while since I last used my slow cooker, so I dusted it off and put it to good use tonight.

This soup calls for an ingredient I've never used before - plum vinegar - which you can find in the Asian section of the grocery store. Don't be alarmed that the ingredients include "beefsteak" leaf. Just like beefsteak tomatoes, this name has nothing to do with actual beef. Beefsteak (also known as shiso) leaf is a member of the mint family, with a taste reminiscent of mint or fennel. In Japanese cuisine, it is frequently eaten with sushi, but we'll skip that application on this blog!

In a slow cooker, combine: 3 and 1/4 cups (1-inch) cubed and peeled sweet potato, 3 cups vegetable broth, 1 cup water, 1/2 cup chopped onion, 1/2 cup orange juice, 2 tablespoons plum vinegar, 2 tablespoons soy sauce (I prefer low-sodium varieties), 1 and 1/2 teaspoons minced and peeled ginger, 1 and 1/2 teaspoons dark sesame oil, 1 teaspoon tamarind paste, 1/4 tsp. black pepper, and 1 lemongrass stalk, cut in half lengthwise.

Cover and set the slow cooker to HIGH - cook for about 5 hours, but don't forget that timing can vary on different models, so your final cook-time may be slightly more or less.

Discard the lemongrass, then transfer the rest of the soup to a blender; process until smooth. (Note: work in two batches if you need to, since you don't want your blender to be filled too high!).

1 cup of soup is 140 calories - this recipe makes enough for about 5 servings.

Cost:
sweet potato $3.64
vegetable broth $3.79
orange juice $1.99
plum vinegar $2.99
ginger $1.24
lemongrass $0.36