Curried Coconut Chicken Soup

First off, this recipe comes from one of my favourite cookbooks and the best slow cooker cookbook I have come across, Art of the Slow Cooker:  80 Exciting New Recipes by Andrew Schloss (p 42).   You can even  find this book on iTunes as an app... great if you are at the market and wondering how much lemongrass you need to pick up!

2 tablespoons vegetable oil, divided
1 1/2 pounds boneless, skinless chicken breast, cut into 1/2-inch cubes
2 medium onions, cut into 1/4-inch dice
1 carrot, peeled and cut into thin slices (I usually put 2, and cut them on the diagonal)
1/2 red pepper, cut into 1/4-by-1-inch strips (I usually use a whole red pepper and 1/2 yellow pepper)
4 cloves garlic, minced
1 tablespoon minced ginger root
1 tablespoon Madras curry powder
4 cups chicken broth
1 teaspoon kosher salt
3 large stalks lemongrass, trimmed and cut into thin slices
1 can (about 14 ounces) coconut milk
2 tablespoons creamy peanut butter (I prefer chunky peanut butter)
2 teaspoons soy sauce (gluten-free of course)
2 teaspoons hot pepper sauce, such as Sriracha
1 teaspoon light brown sugar
1/4 cup coarsely chopped fresh cilantro leaves

Heat half the oil in a large deep skillet over medium heat.  Saute the chicken in 2 batches until it is lightly browned, about 4 minutes per batch, trasfer to a 5-to-6-quart slow cooker.

Add the remaining oil to the skillet and heat.  Add the onions, carrots, and bell peppers

and saute until almost tender, about 3 minutes.  Stir in the garlic, ginger, and curry powder and cook for a few seconds, until aromatic.  Add the broth, salt, and lemongrass and heat to boiling.  Pour into the slow cooker, cover, and cook for 3 to 5 hours on high, or 4 to 8 hours on low, until the broth is full-flavoured and the vegetables are all tender.  

Meanwhile, mix the coconut milk, peanut butter, soy sauce, hot pepper sauce, and brown sugar to combine.  Pour into the cooked soup and cook on high for 15 minutes.  Stir in the cilantro and serve.