Slow Cooker African Groundnut Stew

6 boneless, skinless chicken thighs (about 1 lb)
3 boneless, skinless chicken breasts (about 3/4 lb)
1 medium onion, finely chopped (about 1 C.)
28 oz. can diced tomatoes, undrained
1 3/4 C. chicken broth
2 Tbsp. tomato paste
2 tsp. curry powder
1 tsp. red pepper flakes
1 1/2 lb. dark orange sweet potatoes (3 medium or 4 C.), peeled and cubed
1 lb. small red potatoes (about 12 or 2 1/2 C.), scrubbed and cubed
1 Tbsp. salt
3/4 C. creamy peanut butter

Spray a 5-6 qt. slow cooker with cooking spray. Layer all ingredients, spooning peanut butter in dollops.
Cover; cook on low heat setting 8-10 hrs. Before serving, break up chicken and stir well.