1Heat oil in a Dutch oven over medium-high heat. Sprinkle the chicken with 1/2 teaspoon salt and 1/4 teaspoon pepper. Add the chicken, flesh side down. Cook 10 minutes; turn thighs after 5 minutes. Cool; shred. Discard bones.
2Add onion, leeks, and ginger to the pan; saute 10 minutes. Add the garlic; saute 1 minute.Place parsley sprigs and bay leaves on cheescloth. Gather the edges and tie securely. Add the herb sachet to the pan.
3Combine peanut butter, 1/4 cup water and diced tomatoes, stirring well.
4Add the peanut butter mixture, chicken stock, 2 cups water, sweet potatoes, and ground red pepper to the pan; bring to a boil. Return the chicken to the pan. Reduce heat to medium and simmer 20 minutes, stirring occasionally. Remove from the heat; discard sachet.
5Ladle about 1 1/3 cups soup into each of 6 bowls. Top each serving with 2 teaspoons chopped parsley and 1 teaspoon chopped peanuts.